CD30 is a potential therapeutic target in malignant mesothelioma

Loss of TROP2 and epithelial cell adhesion molecule expression is linked to grade progression in pTa but unrelated to disease outcome in pT2-4 urothelial bladder carcinomas

Introduction

Trophoblast cell surface antigen 2 (TROP2; EpCAM2) is a transmembrane glycoprotein which is closely related to EpCAM (EpCAM; EpCAM1). Both proteins share partial overlapping functions in epithelial development and EpCAM expression but have not been comparatively analyzed together in bladder carcinomas. TROP2 constitutes the target for the antibody-drug conjugate Sacituzumab govitecan (SG; TrodelvyTM) which has been approved for treatment of metastatic urothelial carcinoma by the United States Food and Drug administration (FDA) irrespective of its TROP2 expression status.

Methods

To evaluate the potential clinical significance of subtle differences in TROP2 and EpCAM expression in urothelial bladder cancer, both proteins were analyzed by multiplex fluorescence immunohistochemistry in combination with a deep-learning based algorithm for automated cell detection on more than 2,700 urothelial bladder carcinomas in a tissue microarray (TMA) format.

Results

The staining pattern of TROP2 and EpCAM were highly similar. For both proteins, the staining intensity gradually decreased from pTa G2 low grade (TROP2: 68.8±36.1; EpCAM: 21.5±11.7) to pTa G2 high grade (64.6±38.0; 19.3±12.2) and pTa G3 (52.1±38.7; 16.0±13.0, p<0.001 each). In pT2-4 carcinomas, the average TROP2 and EpCAM staining intensity was intermediate (61.8±40.9; 18.3±12.3). For both proteins, this was significantly lower than in pTa G2 low grade (p<0.001 each) but also higher than in pTa G3 tumors (p=0.022 for TROP2, p=0.071 for EpCAM). Within pT2-4 carcinomas, the TROP2 and EpCAM staining level was unrelated to pT, grade, UICC-category, and overall or tumor-specific patient survival. The ratio TROP2/EpCAM was unrelated to malignant phenotype and patient prognosis.

Conclusion

Our data show that TROP2 and EpCAM expression is common and highly interrelated in urothelial neoplasms. Despite of a progressive loss of TROP2/EpCAM during tumor cell dedifferentiation in pTa tumors, the lack of associations with clinicopathological parameters in pT2-4 cancer argues against a major cancer driving role of both proteins for the progression of urothelial neoplasms.

REDCap and the National Mesothelioma Virtual Bank-a scalable and sustainable model for rare disease biorepositories

OBJECTIVE

Rare disease research requires data sharing networks to power translational studies. We describe novel use of Research Electronic Data Capture (REDCap), a web application for managing clinical data, by the National Mesothelioma Virtual Bank, a federated biospecimen, and data sharing network.

MATERIALS AND METHODS

National Mesothelioma Virtual Bank (NMVB) uses REDCap to integrate honest broker activities, enabling biospecimen and associated clinical data provisioning to investigators. A Web Portal Query tool was developed to source and visualize REDCap data in interactive, faceted search, enabling cohort discovery by public users. An AWS Lambda function behind an API calculates the counts visually presented, while protecting record level data. The user-friendly interface, quick responsiveness, automatic generation from REDCap, and flexibility to new data, was engineered to sustain the NMVB research community.

RESULTS

NMVB implementations enabled a network of 8 research institutions with over 2000 mesothelioma cases, including clinical annotations and biospecimens, and public users' cohort discovery and summary statistics. NMVB usage and impact is demonstrated by high website visits (>150 unique queries per month), resource use requests (>50 letter of interests), and citations (>900) to papers published using NMVB resources.

DISCUSSION

NMVB's REDCap implementation and query tool is a framework for implementing federated and integrated rare disease biobanks and registries. Advantages of this framework include being low-cost, modular, scalable, and efficient. Future advances to NVMB's implementations will include incorporation of -omics data and development of downstream analysis tools to advance mesothelioma and rare disease research.

CONCLUSION

NVMB presents a framework for integrating biobanks and patient registries to enable translational research for rare diseases.

Monoclonal Antibodies in Oncology: A Decade of Novel Options

Several decades of research and clinical trials have conclusively provided proof of concept on the usefulness of monoclonal antibodies in the armamentarium against cancer. There are numerous mAbs approved for both, the treatment of solid tumors as well as hematological malignancies. These have ranked in the top ten best-selling drugs in recent years and one such mAb, pembrolizumab, is slated to be the highest revenue-generating drug by 2024. A large proportion of the mAbs in oncology have been approved by regulatory agencies in just the past decade and many professionals working in the field have been unable to keep abreast with the latest mAbs available and their mechanism of action. In this review, we aim to provide a systematic compilation of the various mAbs in oncology, approved by the US FDA in the past decade. It also elaborates on the mechanism of action of the newly approved mAbs to provide an overall update of the same. For this purpose, we have referred to the Drugs at FDA and relevant articles from PubMed from the year 2010 to date.

Deciphering a cell death-associated signature for predicting prognosis and response to immunotherapy in lung squamous cell carcinoma

BACKGROUND

Lung squamous cell carcinoma (LUSC) is a subtype of non-small cell carcinoma, accounting for about 30% of all lung cancers. Yet, the evaluation of prognostic outcome and therapy response of patients with LUSC remains to be resolved. This study aimed to explore the prognostic value of cell death pathways and develop a cell death-associated signature for predicting prognosis and guiding treatment in LUSC.

METHODS

Transcriptome profiles and corresponding clinical information of LUSC patients were gathered from The Cancer Genome Atlas (TCGA-LUSC, n = 493) and Gene Expression Omnibus database (GSE74777, n = 107). The cell death-related genes including autophagy (n = 348), apoptosis (n = 163), and necrosis (n = 166) were retrieved from the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases. In the training cohort (TCGA-LUSC), LASSO Cox regression was used to construct four prognostic signatures of respective autophagy, apoptosis, and necrosis pathway and genes of three pathways. After comparing the four signatures, the cell death index (CDI), the signature of combined genes, was further validated in the GSE74777 dataset. We also investigated the clinical significance of the CDI signature in predicting the immunotherapeutic response of LUSC patients.

RESULTS

The CDI signature was significantly associated with the overall survival of LUSC patients in the training cohort (HR, 2.13; 95% CI, 1.62‒2.82; P < 0.001) and in the validation cohort (HR, 1.94; 95% CI, 1.01‒3.72; P = 0.04). The differentially expressed genes between the high- and low-risk groups contained cell death-associated cytokines and were enriched in immune-associated pathways. We also found a higher infiltration of naive CD4⁺ T cells, monocytes, activated dendritic cells, neutrophils, and lower infiltration of plasma cells and resting memory CD4⁺ T cells in the high-risk group. Tumor stemness indices, mRNAsi and mDNAsi, were both negatively correlated with the risk score of the CDI. Moreover, LUSC patients in the low-risk group are more likely to respond to immunotherapy than those in the high-risk group (P = 0.002).

CONCLUSIONS

This study revealed a reliable cell death-associated signature (CDI) that closely correlated with prognosis and the tumor microenvironment in LUSC, which may assist in predicting the prognosis and response to immunotherapy for patients with LUSC.

Retinoblastoma Expression and Targeting by CDK4/6 Inhibitors in Small Cell Lung Cancer

The canonical model of "small cell lung cancer" (SCLC) depicts tumors arising from dual inactivation of TP53 and RB1. However, many genomic studies have persistently identified tumors with no RB1 mutations. Here, we examined RB1 protein expression and function in SCLC. RB1 expression was examined by IHC analysis of 62 human SCLC tumors. These studies showed that ∼14% of SCLC tumors expressed abundant RB1 protein, which is associated with neuroendocrine gene expression and is enriched in YAP1 expression, but no other lineage proteins that stratify SCLC. SCLC cells and xenograft tumors with RB1 protein expression were sensitive to growth inhibition by the CDK4/6 inhibitor palbociclib, and this inhibition was shown to be dependent on RB1 expression by CRISPR knockout. Furthermore, a patient with biopsy-validated wild-type RB1 SCLC who received the CDK4/6 inhibitor abemaciclib demonstrated a dramatic decrease in mutant TP53 ctDNA allelic fraction from 62.1% to 0.4% and decreased tumor mass on CT scans. Importantly, IHC of the diagnostic biopsy specimen showed RB1 positivity. Finally, we identified a transcriptomics-based RB1 loss-of-function signature that discriminates between SCLC cells with or without RB1 protein expression and validated it in the patient who was responsive to abemaciclib, suggesting its potential use to predict CDK4/6 inhibitor response in patients with SCLC. Our study demonstrates that RB1 protein is an actionable target in a subgroup of SCLC, a cancer that exhibits no currently targetable mutations.

Biological basis for novel mesothelioma therapies

Mesothelioma is an aggressive cancer that is associated with exposure to asbestos. Although asbestos is banned in several countries, including the UK, an epidemic of mesothelioma is predicted to affect middle-income countries during this century owing to their heavy consumption of asbestos. The prognosis for patients with mesothelioma is poor, reflecting a failure of conventional chemotherapy that has ultimately resulted from an inadequate understanding of its biology. However, recent work has revolutionised the study of mesothelioma, identifying genetic and pathophysiological vulnerabilities, including the loss of tumour suppressors, epigenetic dysregulation and susceptibility to nutrient stress. We discuss how this knowledge, combined with advances in immunotherapy, is enabling the development of novel targeted therapies.

The expression of CD30 and its clinico-pathologic significance in peripheral T-cell lymphomas

INTRODUCTION

Recent studies have shown that CD30 expression can be an important feature of peripheral and cutaneous T-cell lymphomas (PTCLs and CTCLs) and CD30 testing has increased in importance with the emergence of CD30-directed therapy.

AREAS COVERED

This article reviews the literature on CD30-related biology, prevalence, and therapy in patients with PTCL or CTCL. We searched the PubMed database from 1 January 2010 to 28 April 2020, using terms 'CD30' ('peripheral T-cell lymphomas' or 'cutaneous T-cell lymphoma') and 'immunohistochemistry' or 'flow cytometry' or 'pathology,' and synonyms including terms for T-cell lymphoma subtypes.

EXPERT OPINION

CD30 is expressed at relatively high rates of prevalence across a broad range of PTCLs and CTCLs. CD30 expression may be critical to the development of a subset of PTCLs and also a biomarker for treatment choice in some subtypes. Large-scale randomized, controlled studies have shown that CD30-directed treatment with brentuximab vedotin is significantly more effective against CD30-expressing PTCL and CTCL than current standard-of-care regimens. However, accurate CD30 evaluation is limited by inconsistencies in detection methodology and expression cutoffs defining CD30-expressing disease. Greater understanding of CD30 testing and reporting will enable more patients with CD30-expressing PTCL and CTCL to be identified and treated appropriately.

Antiangiogenesis Combined with Immunotherapy to Treat Advanced Small-Cell Carcinoma of the Esophagus Resistant to Chemotherapy: According to the Guidance of Next-Generation Sequencing

A 64-year-old woman admitted to our hospital with the chief complaint of swallowing obstruction was diagnosed as relapsed small-cell carcinoma of the esophagus. Complete remission (CR) was observed after six cycles of irinotecan plus cisplatin therapy. According to the results of a next-generation sequencing analysis of the tumor specimen, anlotinib (12 mg PO q3w) was recommended. After 1 month of anlotinib treatment, the tumor decreased significantly according to computed tomography scan and gastroscopy. However, the disease progressed after 2 months of therapy. A gene analysis of the new puncture sample showed microsatellite instability and a high tumor mutation burden. Immunohistochemistry indicated positive programmed death ligand-1 expression (>1%). Because of these results, the patient was treated with anlotinib (12 mg PO q3w) in combination with toripalimab (240 mg IV drip q3w). After 3 months of therapy, CR was achieved, although progression-free survival had not been reached at the time of publication.

Application of flow cytometry in the analysis of lymphoid disease in the lung and pleural space

Various types of lymphoid neoplasms can occur in the lung. Lung parenchyma, the pleura or the pleural cavity can be the primary site of a lymphoid neoplasm or can be involved secondarily as a result of systemic dissemination from a separate primary site. Recognition of pulmonary lymphoid neoplasms (PLN) has increased secondary to technological advances in the medical field. Multiparameter flow cytometry (FC) is a one of the diagnostic tools that serves an essential role in the detecting and categorizing PLNs. FC allows for rapid identification and immunophenotypic characterization of PLN. In this article, we discuss the role of FC in the diagnosis of the most commonly encountered PLNs as well as their basic clinicopathologic features. We briefly discuss the role of FC in identifying non-hematolymphoid neoplasms in lung specimens as well.

Practical Approaches on CD30 Detection and Reporting in Lymphoma Diagnosis

While our understanding of the biology of CD30 in lymphoma continues to evolve, our need to detect and measure its expression at the protein level remains critically important for diagnosis and patient care. In addition to its diagnostic and prognostic utility, CD30 has emerged as a vehicle for drug targeting through the antibody-drug conjugate brentuximab-vedotin (BV). Given the numerous ways that CD30 is utilized and its emergence as a predictive/prognostic biomarker, pathologists must come to a general consensus on the best reporting structure and methodology to ensure appropriate patient care. In this manuscript, we review the indications for testing, various modalities for testing, technical challenges, pitfalls, and potential standards of reporting. The following questions will try to be addressed in the current review article: What defines a "POSITIVE" level of CD30 expression?; How do we evaluate and report CD30 expression?; What are the caveats in the evaluation of CD30 expression?

Workshop summary: Potential usefulness and feasibility of a US National Mesothelioma Registry

The burden and prognosis of malignant mesothelioma in the United States have remained largely unchanged for decades, with approximately 3200 new cases and 2400 deaths reported annually. To address care and research gaps contributing to poor outcomes, in March of 2019 the Mesothelioma Applied Research Foundation convened a workshop on the potential usefulness and feasibility of a national mesothelioma registry. The workshop included formal presentations by subject matter experts and a moderated group discussion. Workshop participants identified top priorities for a registry to be (a) connecting patients with high-quality care and clinical trials soon after diagnosis, and (b) making useful data and biospecimens available to researchers in a timely manner. Existing databases that capture mesothelioma cases are limited by factors such as delays in reporting, deidentification, and lack of exposure information critical to understanding as yet unrecognized causes of disease. National disease registries for amyotrophic lateral sclerosis (ALS) in the United States and for mesothelioma in other countries, provide examples of how a registry could be structured to meet the needs of patients and the scientific community. Small-scale pilot initiatives should be undertaken to validate methods for rapid case identification, develop procedures to facilitate patient access to guidelines-based standard care and investigational therapies, and explore approaches to data sharing with researchers. Ultimately, federal coordination and funding will be critical to the success of a National Mesothelioma Registry in improving mesothelioma outcomes and preventing future cases of this devastating disease.

Crizotinib enhances anti-CD30-LDM induced antitumor efficacy in NPM-ALK positive anaplastic large cell lymphoma

Combining antibody-drug conjugates (ADCs) with targeted small-molecule inhibitors can enhance antitumor effects beyond those attainable with monotherapy. In this study, we investigated the therapeutic combination of a CD30-targeting ADC (anti-CD30-lidamycin [LDM]) with a small-molecule inhibitor (crizotinib) of nucleophosmin-anaplastic lymphoma kinase NPM-ALK in CD30⁺/ALK⁺ anaplastic large cell lymphoma (ALCL). In vitro, anti-CD30-LDM showed strong synergistic antiproliferative activity when combined with crizotinib. Furthermore, treatment with anti-CD30-LDM plus crizotinib resulted in a stronger induction of cell apoptosis than monotherapy with either treatment. Western blot analysis revealed that ERK1/2 phosphorylation was increased in response to anti-CD30-LDM-induced DNA damage. Interestingly, the addition of crizotinib inhibited the expression of phosphorylated ERK1/2 and further augmented anti-CD30-LDM-mediated apoptosis, providing a potential synergistic mechanism for DNA-damaging agents combined with NPM-ALK inhibitors. In Karpas299 and SU-DHL-1 xenograft models, anti-CD30-LDM plus crizotinib was more effective in inhibiting tumor growth than either treatment alone. This research demonstrated for the first time that the combination of anti-CD30-LDM and crizotinib exhibits a synergistic inhibitory effect in tumor cells. These results provide scientific support for future clinical evaluations of anti-CD30-LDM, or other DNA-damaging agents, combined with NPM-ALK inhibitors.

Antibody drug conjugates in thoracic malignancies

Antibody drug conjugates (ADCs) have the potential to alter the efficacy: toxicity ratio of cytotoxic therapy utilizing surface markers on cancer cells as antibody targets to preferentially deliver toxic payloads to tumor cells while limiting systemic toxicity. Multiple ADCs, differing in their antibody targets, cytotoxic payloads and linker molecules are currently being evaluated in non-small-cell lung cancer, small-cell lung cancer and malignant pleural mesothelioma. Here we review the available data in thoracic malignancies and the potential issues influencing the efficacy and toxicity of these approaches.

Noninvasive Trafficking of Brentuximab Vedotin and PET Imaging of CD30 in Lung Cancer Murine Models

CD30 has been considered a unique diagnostic and therapeutic target for CD30-positive lymphomas and some lung diseases. Additionally, CD30 has shown high expression in clinical lung cancer samples. In this study, ⁸⁹Zr-radiolabeled brentuximab vedotin (BV) was developed for in vivo tracking of BV and imaging CD30 expression in lung cancer models via conjugation with desferrioxamine (Df). CD30 expression in three lung cancer cell lines (H460, H358, and A549) was quantified by Western blot. Flow cytometry and saturation binding assays were used to evaluate the binding capabilities of the tracer in vitro. After longitudinal positron emission tomography (PET) imaging and quantitative analysis were performed, ex vivo biodistribution and histological studies were used to verify PET results. Finally, dosimetric extrapolation of murine data to humans was performed. At the cellular level, CD30 was found to be expressed on H460 and A549 cells with the highest and lowest levels of expression, respectively. Both Df-BV and ⁸⁹Zr-Df-BV displayed high binding affinity to H460 cells. PET images and their quantification verified that BV accumulated in H460 tumor models (9.93 ± 2.70% ID/g at 24 h after injection; n = 4) at the highest level, followed by H358 and A549 tumors (8.05 ± 2.43 and 5.00 ± 1.56% ID/g; n = 4). The nonspecific ⁸⁹Zr-labeled IgG showed a low tumor uptake of 5.2 ± 1.0% ID/g for H460 models. Ex vivo biodistribution and fluorescence immunohistochemistry also corroborated these findings. Dosimetric results displayed safe dose estimations. Therefore, ⁸⁹Zr-Df-BV provides a potential agent for evaluating CD30 expression noninvasively in lung cancer, and also for imaging of brentuximab vedotin for better understanding of its pharmacokinetics.

Advances in systemic therapy for malignant mesothelioma: future perspectives

Malignant mesothelioma is a rare and aggressive form of cancer affecting the mesothelium. This mainly occupational disease is becoming more common in those countries where asbestos has been used for industrial applications. Notwithstanding the progress made in the field, patients do not survive more than 12 months on average with standard treatment. With the advent of next generation sequencing, it is now possible to study the mutational landscape of each tumor with the aim of identifying the genetic aberrations driving tumorigenesis. This review encompasses the latest research in the field, with particular attention to new chemotherapy combinatorial regimens, molecular targets and immunotherapies, providing a comprehensive picture of the current and future treatment options for malignant mesothelioma patients.

Reciprocal expression of INSM1 and YAP1 defines subgroups in small cell lung cancer

The majority of small cell lung cancer (SCLC) patients demonstrate initial chemo-sensitivity, whereas a distinct subgroup of SCLC patients, termed chemo-refractory, do not respond to treatment. There is little understanding of how to distinguish these patients prior to disease treatment. Here we used gene expression profiling to stratify SCLC into subgroups and characterized a molecular phenotype that may identify, in part, chemo-refractive SCLC patients. Two subgroups of SCLC were identified in both cell lines and tumors by the reciprocal expression of two genes; INSM1, a neuroendocrine transcription factor, and YAP1, a key mediator of the Hippo pathway. The great majority of tumors expressed INSM1, which was prognostic for increased progression-free survival and associated with chemo-sensitivity in cell lines. YAP1 is expressed in a minority of SCLC tumors and was shown in cell lines to be downstream of the retinoblastoma protein (RB1) and associated with decreased drug sensitivity. RB1 expression in SCLC cell lines sensitizes them to CDK4/6 inhibitors. Wild-type RB1 mutation status, used as a surrogate marker of YAP1 expression, was prognostic for decreased patient survival and increased chemo-refractory tumor response. Thus, the reciprocal expression of INSM1 and YAP1 appears to stratify SCLC into distinct subgroups and may be useful, along with RB1 mutation status, to identify chemo-refractory SCLC patients.

CD30 Expression in Pediatric Neoplasms, Study of 585 Cases

CD30 is a member of the tumor necrosis factor receptor superfamily, member 8 (TNFRSF8), and its normal expression is restricted to activated T and B cells. In tumor cells, CD30 expression is most commonly associated with lymphoid malignancies (Hodgkin and non-Hodgkin lymphomas) and is a therapeutic target using anti-CD30 antibody. CD30 expression has been reported also in mostly adult non-lymphoid malignancies, raising the possibility of CD30-targeted therapy for additional tumors. In this study, we examined the incidence of CD30 expression in 251 hematopoietic and 334 non-hematopoietic cases of pediatric tumors. As expected, strong and membranous CD30 staining was seen in anaplastic large cell lymphoma, classical Hodgkin lymphoma, and embryonal carcinoma while variable staining was seen in diffuse large B cell lymphoma. In addition, positive CD30 staining was also seen in cases of neuroblastoma (33 of 56), neoplasm with chondroid differentiation (8 of 25), myeloid neoplasms (11 of 120), hemangioma (2 of 12), and mature teratoma (1 of 11). In neuroblastoma, the CD30 expression was generally restricted to cells with ganglion differentiation; staining of ganglion cells was also seen in the one positive case of mature teratoma. In neoplasm with chondroid differentiation, the positive cases were chondrosarcoma (3 of 5), chondroblastic osteosarcoma (2 of 10), and chondroblastoma (3 of 7). In acute myeloid leukemia, the CD30 positive cases were more common in AML with monocytic differentiation but did not correlate with any specific molecular change. We conclude that CD30 expression in pediatric tumors is more general than anticipated and future studies are warranted to understand the biologic and therapeutic significances.

Potential application and prevalence of the CD30 (Ki-1) antigen among solid tumors: A focus review of the literature

BACKGROUND

CD30 (Ki-1) is a cell membrane protein derived from the tumor necrosis factor (TNF) receptor family. The CD30 antigen has been associated primarily with Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL). Brentuximab vedotin (BV) is an antibody-drug conjugate targeting the CD30 antigen. FDA approval for BV includes relapsed and refractory HL and sALCL. The CD30 antigen also has been identified in many solid tumors, predominantly of germ cell origins and early clinical data is promising.

OBJECTIVE

Perform a focus literature review evaluating the prevalence of the CD30 antigen among nonlymphomatous tumors with a potential correlate for CD30 targeted therapy.

ELIGIBILITY CRITERIA

Inclusion criteria: all retrospective reviews and case reports citing CD30 positivity or negativity in non-lymphomatous malignancies in which data were presented based on location.

EXCLUSION CRITERIA

studies with hematopoetic malignancies, cutaneous malignancies, non-human populations, and non-english publications.

INCLUDED STUDIES

A total of 119 articles met these criteria and are summarized in this manuscript.

CONCLUSION

The CD30 antigen has shown variable prevalence among non-hematopoetic tumors, most notably among germ cell tumors and mesothelioma. With additional, preclinical and properly powered clinical studies, CD30 targeted therapy such as that of BV, alone or in combination with other agents may prove to be a strong candidate in the treatment of various CD30⁺ malignancies.

Mechanisms of action of therapeutic antibodies for cancer

The therapeutic utility of antibodies and their derivatives is achieved by various means. The FDA has approved several targeted antibodies that disrupt signaling of various growth factor receptors for the treatment of a number of cancers. Rituximab, and other anti-CD20 monoclonal antibodies are active in B cell malignancies. As more experience has been gained with anti-CD20 monoclonal antibodies, the multifactorial nature of their anti-tumor mechanisms has emerged. Other targeted antibodies function to dampen inhibitory checkpoints. These checkpoint inhibitors have recently achieved dramatic results in several cancers, including melanoma. These and related antibodies continue to be investigated in the clinical and pre-clinical settings. Novel antibody structures that target two or more antigens have also made their way into clinical use. Tumor targeted antibodies can also be conjugated to chemo- or radiotherapeutic agents, or catalytic toxins, as a means to deliver toxic payloads to cancer cells. Here we provide a review of these mechanisms and a discussion of their relevance to current and future clinical applications.