Emerging treatment for advanced lung cancer withEGFRmutation

The Importance of HHLA2 in Solid Tumors-A Review of the Literature

Cancer immunotherapy is a rapidly developing field of medicine that aims to use the host's immune mechanisms to inhibit and eliminate cancer cells. Antibodies targeting CTLA-4, PD-1, and its ligand PD-L1 are used in various cancer therapies. However, the most thoroughly researched pathway targeting PD-1/PD-L1 has many limitations, and multiple malignancies resist its effects. Human endogenous retrovirus-H Long repeat-associating 2 (HHLA2, known as B7H5/B7H7/B7y) is the youngest known molecule from the B7 family. HHLA2/TMIGD2/KIRD3DL3 is one of the critical pathways in modulating the immune response. Recent studies have demonstrated that HHLA2 has a double effect in modulating the immune system. The connection of HHLA2 with TMIGD2 induces T cell growth and cytokine production via an AKT-dependent signaling cascade. On the other hand, the binding of HHLA2 and KIR3DL3 leads to the inhibition of T cells and mediates tumor resistance against NK cells. This review aimed to summarize novel information about HHLA2, focusing on immunological mechanisms and clinical features of the HHLA2/KIR3DL3/TMIGD2 pathway in the context of potential strategies for malignancy treatment.

Coevolution-based computational approach to detect resistance mechanism of epidermal growth factor receptor

Tyrosine kinase epidermal growth factor receptor (EGFR) correlates the neoplastic cell metastasis, angiogenesis, neoplastic incursion, and apoptosis. Due to the involvement of EGFR in these biological processes, it becomes a most potent target for treating non-small cell lung cancer (NSCLC). The tyrosine kinase inhibitors (TKI) have endorsed high efficacy and anticipation to patients but unfortunately, within a year of treatment, drug targets develop resistance due to mutations. The present study detected the compensatory mutations in EGFR to know the evolutionary mechanism of drug resistance. The results of this study demonstrate that compensatory mutations enlarge the drug-binding pocket which may lead to the altered orientation of the ligand (gefitinib and erlotinib) causing drug resistance. This indicates that coevolutionary forces play a significant role in fine-tuning the structure of EGFR protein against the drugs. The analysis provides insight into the evolution-induced structural aspects of drug resistance changes in EGFR which in turn be useful in designing drugs with better efficacy.

An Overview of EGFR Mechanisms and Their Implications in Targeted Therapies for Glioblastoma

Despite all of the progress in understanding its molecular biology and pathogenesis, glioblastoma (GBM) is one of the most aggressive types of cancers, and without an efficient treatment modality at the moment, it remains largely incurable. Nowadays, one of the most frequently studied molecules with important implications in the pathogenesis of the classical subtype of GBM is the epidermal growth factor receptor (EGFR). Although many clinical trials aiming to study EGFR targeted therapies have been performed, none of them have reported promising clinical results when used in glioma patients. The resistance of GBM to these therapies was proven to be both acquired and innate, and it seems to be influenced by a cumulus of factors such as ineffective blood-brain barrier penetration, mutations, heterogeneity and compensatory signaling pathways. Recently, it was shown that EGFR possesses kinase-independent (KID) pro-survival functions in cancer cells. It seems imperative to understand how the EGFR signaling pathways function and how they interconnect with other pathways. Furthermore, it is important to identify the mechanisms of drug resistance and to develop better tailored therapeutic agents.

Machine learning application in personalised lung cancer recurrence and survivability prediction

Machine learning is an important artificial intelligence technique that is widely applied in cancer diagnosis and detection. More recently, with the rise of personalised and precision medicine, there is a growing trend towards machine learning applications for prognosis prediction. However, to date, building reliable prediction models of cancer outcomes in everyday clinical practice is still a hurdle. In this work, we integrate genomic, clinical and demographic data of lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) patients from The Cancer Genome Atlas (TCGA) and introduce copy number variation (CNV) and mutation information of 15 selected genes to generate predictive models for recurrence and survivability. We compare the accuracy and benefits of three well-established machine learning algorithms: decision tree methods, neural networks and support vector machines. Although the accuracy of predictive models using the decision tree method has no significant advantage, the tree models reveal the most important predictors among genomic information (e.g. KRAS, EGFR, TP53), clinical status (e.g. TNM stage and radiotherapy) and demographics (e.g. age and gender) and how they influence the prediction of recurrence and survivability for both early stage LUAD and LUSC. The machine learning models have the potential to help clinicians to make personalised decisions on aspects such as follow-up timeline and to assist with personalised planning of future social care needs.

Self-Expandable Metallic Stent Implantation Combined With Bronchial Artery Infusion Chemoembolization in the Treatment of Lung Cancer With Complete Atelectasis

Background

Atelectasis is a common complication of lung cancer, and there are few reports about the treatment methods. This study retrospectively analyzed the safety and effectiveness of endotracheal metal stent implantation combined with arterial infusion chemoembolization in the treatment of non-small cell lung cancer with complete atelectasis.

Methods

The clinical data of patients with non-small cell lung cancer and complete atelectasis treated by self-expandable metallic stent implantation combined with arterial infusion chemotherapy were retrospectively analyzed. The clinical efficacy was evaluated and postoperative adverse reactions were observed. Progression-free survival and overall survival were analyzed by Kaplan-Meier method.

Results

In all, 42 endotracheal metallic stents were implanted in 42 patients under fluoroscopy. 5–7 days after stent implantation, CT showed that 24 patients (57.1%) had complete lung recruitment, and that 13 (31.0%) had partial lung recruitment. The technical success rate was 100%, and the clinical success rate was 88.1% (37/42). 5–7 days after stent implantation, bronchial artery infusion chemoembolization was performed in all patients. The median progression-free survival and overall survival were 6 months (95% CI: 2.04-9.66) and 10 months (95% CI: 7.22-12.79), respectively.

Conclusion

Self-expandable metallic stent implantation combined with arterial infusion chemoembolization may be an effective and safe strategy in the treatment of lung cancer with atelectasis clinically.

Sintilimab plus Bronchial Arterial Infusion Chemotherapy/Drug-Eluting Embolic Chemoembolization for Advanced Non-Small Cell Lung Cancer: A Preliminary Study of 10 Patients

PURPOSE

To evaluate the short-term efficacy and safety of immunotherapy with sintilimab combined with bronchial arterial infusion (BAI) chemotherapy/drug-eluting embolic (DEE) bronchial arterial chemoembolization (BACE) for advanced non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Ten patients with advanced NSCLC were treated with sintilimab plus BAI/DEE-BACE between December 2019 and November 2020 and retrospectively evaluated. The Response Evaluation Criteria in Solid Tumors version 1.1 was applied to evaluate the treatment response. The local tumor control duration, progression-free survival (PFS), and overall survival (OS) were estimated using the Kaplan-Meier analysis.

RESULTS

At 30 days after the last multimodal treatment, complete response, partial response, and stable disease were recorded in 1 (10%), 7 (70%), and 2 (20%) patients, respectively, for an objective response rate of 80% and a disease control rate of 100%. No patient experienced progressive disease. The median duration of local tumor control was 8.0 months (95% CI, 6.2-9.7 months). The median PFS and OS were 11.0 months (95% CI, 6.9-15.1 months) and 8.0 months (95% CI, 5.5-10.5 months), respectively. Two cases of Grade III adverse events related to medications were reported.

CONCLUSIONS

Sintilimab combined with BAI/DEE-BACE for patients with advanced NSCLC appears to be safe and feasible. Compared with previous studies on BAI/DEE-BACE, the addition of immunotherapy may improve survival.

Current progress, challenges and future prospects of indazoles as protein kinase inhibitors for the treatment of cancer

The indazole core is an interesting pharmacophore due to its applications in medicinal chemistry. In the past few years, this moiety has been used for the synthesis of kinase inhibitors. Many researchers have demonstrated the use of indazole derivatives as specific kinase inhibitors, including tyrosine kinase and serine/threonine kinases. A number of anticancer drugs with an indazole core are commercially available, e.g. axitinib, linifanib, niraparib, and pazopanib. Indazole derivatives are applied for the targeted treatment of lung, breast, colon, and prostate cancers. In this review, we compile the current development of indazole derivatives as kinase inhibitors and their application as anticancer agents in the past five years.

EGFR tyrosine kinase inhibitor Almonertinib induces apoptosis and autophagy mediated by reactive oxygen species in non-small cell lung cancer cells

Almonertinib, a new third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is highly selective to EGFR T790M-mutant non-small cell lung cancer (NSCLC). However, there is no available information on the form and molecular mechanism of Almonertinib-induced death in NSCLC cells. Herein, CCK-8 and colony formation assays, flow cytometry, electron microscopy, and western blots assay showed that Almonertinib inhibited NSCLC cells growth and proliferation by inducing apoptosis and autophagy which can be inhibited by a broad spectrum of caspase inhibitor Z-VAD-fmk or autophagy inhibitor chloroquine. Importantly, Almonertinib-induced autophagy was cytoprotective in NSCLC cells, and the blockade of autophagy improved cell apoptosis. In addition, Almonertinib increased reactive oxygen species (ROS) generation and clearance of ROS through pretreatment with N-acetyl-L-cysteine (NAC) inhibited the decrease of cell viability, apoptosis and increase of LC3-II induced by Almonertinib. The results of Western blot showed that both EGFR activity and downstream signaling pathways were inhibited by Almonertinib. Taken together, these findings indicated that Almonertinib induced apoptosis and autophagy by promoting ROS production in NSCLC cells.

Combination of Bronchial Arterial Infusion Chemotherapy plus Drug-Eluting Embolic Transarterial Chemoembolization for Treatment of Advanced Lung Cancer-A Retrospective Analysis of 23 Patients

PURPOSE

To determine the efficacy and safety of the combination of bronchial arterial infusion (BAI) chemotherapy and transarterial chemoembolization with the use of drug-eluting embolic (DEE) particles in the treatment of unresectable advanced lung cancer.

MATERIALS AND METHODS

A retrospective review was performed of 23 patients with unresectable lung cancer (stage III/IV) who received BAI chemotherapy and DEE chemoembolization. Treatment response was assessed by enhanced CT and evaluated on the basis of Response Evaluation Criteria In Solid Tumors at 30 d after the last combination treatment. Patients were followed up until death or March 15, 2020, whichever was first. Overall survival (OS) was estimated by Kaplan-Meier analysis, and factors associated with OS were evaluated by Cox proportional-hazards test.

RESULTS

Complete response, partial response, stable disease, and progressive disease were seen in 2, 16, 5, and 0 patients at 30 d after the last combination treatment, respectively; therefore, the overall response rate was 78.3% and the disease control rate was 100%. Preprocedure symptoms (hemoptysis in 7 patients and dyspnea in 10) resolved in all cases after combination therapy. Nineteen patients died during follow-up, and 4 survived. Median OS was 15.6 mo (95% confidence interval, 10.1-21.1 mo). On univariate analysis and multivariate analysis, tumor/node/metastasis staging was an independent risk factor for prognosis. There were no serious adverse events during the procedures.

CONCLUSIONS

The combination of BAI chemotherapy plus DEE chemoembolization appears to be a promising method for treatment of advanced lung cancer.

Spred-3 mutation and Ras/Raf/MAPK activation confer acquired resistance to EGFR tyrosine kinase inhibitor in an EGFR mutated NSCLC cell line

Background

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are standard treatment for advanced non-small cell lung cancer (NSCLC). However, the emergence of EGFR-TKIs resistance poses a big challenge to the treatment. Although several resistant mutations have been identified, our understanding of the mechanisms underlying acquired EGFR-TKIs resistance remains incomplete. This study aimed to identify novel mutations and mechanisms that could contribute to acquired EGFR-TKIs resistance in EGFR mutated NSCLC cells.

Methods

Erlotinib resistant cells (HCC827/ER cells) were generated from the EGFR mutated NSCLC cell line HCC827, and whole-exome sequencing was performed to identify gene mutations in HCC827/ER cells. The Spred-3 expression was determined using quantitative real-time PCR (qPCR) and Western blotting assays, and the p-p44/42, p44/42, p-Akt and Akt expression was determined using Western blotting. The half maximal inhibitory concentration (IC₅₀ value) was measured using the MTS assay, and cell migration was detected with a Transwell migration assay.

Results

Whole-exome sequencing identified deletion mutation c.120delG at exon 1 of the Spred-3 gene, resulting in a p.E40fs change in amino acid, in HCC827/ER cells. The Spred-3 expression was much reduced in HCC827/ER cells as compared to the HCC827 cells at both mRNA and protein levels. Knocking out Spred-3 in HCC827 cells using CRISPR/Cas9 increased erlotinib resistance and cell migration, while overexpressing Spred-3 in HCC827/ER cells using a cDNA construct reduced erlotinib resistance and cell migration. We also showed the Ras/Raf/MAPK pathway was activated in HCC827/ER cells, and inhibiting ERK1/2 in HCC827/Spred-3-sgRNA cells resulted in reduced erlotinib resistance and cell migration.

Conclusions

The results of this study indicate that a loss-of-function mutation in Spred-3 resulted in activation of the Ras/Raf/MAPK pathway that confers resistance to EGFR-TKIs in NSCLC cells harboring an EGFR mutation.

Targeting Autophagy for Overcoming Resistance to Anti-EGFR Treatments

Epidermal growth factor receptor (EGFR) plays critical roles in cell proliferation, tumorigenesis, and anti-cancer drug resistance. Overexpression and somatic mutations of EGFR result in enhanced cancer cell survival. Therefore, EGFR can be a target for the development of anti-cancer therapy. Patients with cancers, including non-small cell lung cancers (NSCLC), have been shown to response to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and anti-EGFR antibodies. However, resistance to these anti-EGFR treatments has developed. Autophagy has emerged as a potential mechanism involved in the acquired resistance to anti-EGFR treatments. Anti-EGFR treatments can induce autophagy and result in resistance to anti-EGFR treatments. Autophagy is a programmed catabolic process stimulated by various stimuli. It promotes cellular survival under these stress conditions. Under normal conditions, EGFR-activated phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) signaling inhibits autophagy while EGFR/rat sarcoma viral oncogene homolog (RAS)/mitogen-activated protein kinase kinase (MEK)/mitogen-activated protein kinase (MAPK) signaling promotes autophagy. Thus, targeting autophagy may overcome resistance to anti-EGFR treatments. Inhibitors targeting autophagy and EGFR signaling have been under development. In this review, we discuss crosstalk between EGFR signaling and autophagy. We also assess whether autophagy inhibition, along with anti-EGFR treatments, might represent a promising approach to overcome resistance to anti-EGFR treatments in various cancers. In addition, we discuss new developments concerning anti-autophagy therapeutics for overcoming resistance to anti-EGFR treatments in various cancers.

Rethink of EGFR in Cancer With Its Kinase Independent Function on Board

The epidermal growth factor receptor (EGFR) is one of most potent oncogenes that are commonly altered in cancers. As a receptor tyrosine kinase, EGFR's kinase activity has been serving as the primary target for developing cancer therapeutics, namely the EGFR inhibitors including small molecules targeting its ATP binding pocket and monoclonal antibodies targeting its ligand binding domains. EGFR inhibitors have produced impressive therapeutic benefits to responsive types of cancers. However, acquired and innate resistances have precluded current anti-EGFR agents from offering sustainable benefits to initially responsive cancers and benefits to EGFR-positive cancers that are innately resistant. Recent years have witnessed a realization that EGFR possesses kinase-independent (KID) pro-survival functions in cancer cells. This new knowledge has offered a different angle of understanding of EGFR in cancer and opened a new avenue of targeting EGFR for cancer therapy. There are already many excellent reviews on the role of EGFR with a focus on its kinase-dependent functions and mechanisms of resistance to EGFR targeted therapies. The present opinion aims to initiate a fresh discussion about the function of EGFR in cancer cells by laying out some unanswered questions pertaining to EGFR in cancer cells, by rethinking the unmet therapeutic challenges from a view of EGFR's KID function, and by proposing novel approaches to target the KID functions of EGFR for cancer treatment.

Opportunities and challenges of co-targeting epidermal growth factor receptor and autophagy signaling in non-small cell lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are a standard therapy for patients with non-small cell lung cancer (NSCLC) with sensitive mutations. However, acquired resistance emerges following a median of 6-12 months. Several studies demonstrated that EGFR-TKI-induced tumor microenvironment stresses and autophagy are important causes of resistance. The current review summarizes the molecular mechanisms involved in EGFR-mediated regulation of autophagy. The role of autophagy in EGFR-TKI treatment, which may serve a role in protection or cell death, was discussed. Furthermore, co-inhibiting EGFR and autophagy signaling as a rational therapeutic strategy in the treatment of patients with NSCLC was explored.

Salivary Exosomes as Nanocarriers for Cancer Biomarker Delivery

Human saliva is an ideal body fluid for developing non-invasive diagnostics. Saliva contains naturally-occurring nanoparticles with unique structural and biochemical characteristics. The salivary exosome, a nanoscale extracellular vesicle, has been identified as a highly informative nanovesicle with clinically-relevant information. Salivary exosomes have brought forth a pathway and mechanism by which cancer-derived biomarkers can be shuttled through the systemic circulation into the oral cavity. Despite such clinical potential, routine and reliable analyses of exosomes remain challenging due to their small sizes. Characterization of individual exosome nanostructures provides critical data for understanding their pathophysiological condition and diagnostic potential. In this review, we summarize a current array of discovered salivary biomarkers and nanostructural properties of salivary exosomes associated with specific cancers. In addition, we describe a novel electrochemical sensing technology, EFIRM (electric field-induced release and measurement), that advances saliva liquid biopsy, covering the current landscape of point-of-care saliva testing.

Cost-utility of afatinib and gefitinib as first-line treatment for EGFR-mutated advanced non-small-cell lung cancer

Aim: To evaluate the cost-utility of gefitinib and afatinib as first-line EGFR-mutated non-small-cell lung cancer treatments from the Chinese healthcare system perspective. Materials & methods: A Markov model was established, state transition probabilities were extracted from the LUX-Lung7 trial and utility values were from previous studies. The cost was extracted from local charge or relevant literature. Incremental cost–effectiveness ratio was calculated for intention-to-treat, EGFR exon 19 deletion (del19) and exon Leu858Arg (21L858R, L858R) muation subgroups.  Results: For the entire population, the afatinib regimen afforded additional 0.29 quality-adjusted life years (QALYs). Incremental cost–effectiveness ratios were US$9820.41/QALY, US$18,529.65/QALY and US$1585.51/QALY for intention-to-treat, L858R and del19, respectively. Conclusion: First-line afatinib was more cost–effective than gefitinib for EFGR-mutated advanced non-small-cell lung cancer in China.

Suppression of lung cancer progression by isoliquiritigenin through its metabolite 2, 4, 2', 4'-Tetrahydroxychalcone

Background

Licorice is an herb extensively used for both culinary and medicinal purposes. Various constituents of licorice have been shown to exhibit anti-tumorigenic effect in diverse cancer types. However, majority of these studies focus on the aspect of their growth-suppressive role. In this study, we systematically analyzed known licorice’s constituents on the goal of identifying component(s) that can effectively suppress both cell migration and growth.

Methods

Effect of licorice’s constituents on cell growth was evaluated by MTT assay while cell migration was assessed by both wound-healing and Transwell assays. Cytoskeleton reorganization and focal adhesion assembly were visualized by immunofluorescence staining with labeled phalloidin and anti-paxillin antibody. Activity of Src in cells was judged by western blot using phosphor-Src416 antibody while Src kinase activity was measured using Promega Src kinase assay system. Anti-tumorigenic capabilities of isoliquiritigenin (ISL) and 2, 4, 2′, 4’-Tetrahydroxychalcone (THC) were investigated using lung cancer xenograft model.

Results

Using a panel of lung cancer cell lines, ISL was identified as the only licorice’s constituent capable of inhibiting both cell migration and growth. ISL-led inhibition in cell migration resulted from impaired cytoskeleton reorganization and focal adhesion assembly. Assessing the phosphorylation of 141 cytoskeleton dynamics-associated proteins revealed that ISL reduced the abundance of Tyr421-phosphorylation of cortactin, Tyr925- and Tyr861-phosphorylation of FAK, indicating the involvement of Src because these sites are known to be phosphorylated by Src. Enigmatically, ISL inhibited Src in cells while displayed no effect on Src activity in cell-free system. The discrepancy was explained by the observation that THC, one of the major ISL metabolite identified in lung cancer cells abrogated Src activity both in cells and cell-free system. Similar to ISL, THC deterred cell migration and abolished cytoskeleton reorganization/focal adhesion assembly. Furthermore, we showed both ISL and THC suppressed in vitro lung cancer cell invasion and in vivo tumor progression.

Conclusion

Our study suggests that ISL inhibits lung cancer cell migration and tumorigenesis by interfering with Src through its metabolite THC. As licorice is safely used for culinary purposes, our study suggests that ISL or THC may be safely used as a Src inhibitor.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0902-4) contains supplementary material, which is available to authorized users.

Kinases and Cancer

Protein kinases are a large family of enzymes catalyzing protein phosphorylation. The human genome contains 518 protein kinase genes, 478 of which belong to the classical protein kinase family and 40 are atypical protein kinases [...].

Down-regulation of miR-214 reverses erlotinib resistance in non-small-cell lung cancer through up-regulating LHX6 expression

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are standard treatments for advanced non-small-cell lung cancer (NSCLC) patients. However, acquired resistance to EGFR-TKIs is widely detected across the world, and the exact mechanisms have not been fully demonstrated until now. This study aimed to examine the role of miR-214 in the acquired resistance to erlotinib in NSCLC, and elucidate the underlying mechanisms. qRT-PCR assay detected higher miR-214 expression in the plasma of NSCLC patients with acquired EGFR-TKI resistance than prior to EGFR-TKI therapy, and in the generated erlotinib-resistant HCC827 (HCC827/ER) cells than in HCC827 cells. Bioinformatics analysis and dual-luciferase reporter assay indentified LHX6 as a direct target gene of miR-214, and LHX6 expression was detected to be down-regulated in erlotinib-resistant HCC827 cells. Transwell invasion assay revealed that overexpressing LHX6 reversed the increase in the invasive ability of HCC827 cells induced by miR-214 overexpression, and the CRISPR-Cas9 system-mediated LHX6 knockdown reversed the reduction in the invasion of erlotinib-resistant HCC827 cells caused by miR-214 down-regulation. The results of the present study demonstrate that down-regulation of miR-214 may reverse acquired resistance to erlotinib in NSCLC through mediating its direct target gene LHX6 expression.

HHLA2, a New Immune Checkpoint Member of the B7 Family, Is Widely Expressed in Human Lung Cancer and Associated with EGFR Mutational Status

PURPOSE

Immunotherapy with antibodies against B7/CD28 family members, including PD-1, PD-L1, and CTLA-4 has shifted the treatment paradigm for non-small cell lung carcinoma (NSCLC) with improved clinical outcome. HHLA2 is a newly discovered member of the family. By regulating T-cell function, HHLA2 could contribute to tumor immune suppression and thus be a novel target for cancer immunotherapy. There is limited information and critical need to characterize its expression profile and clinical significance in NSCLC.

EXPERIMENTAL DESIGN

We performed IHC with an HHLA2-specific antibody (clone 566.1) using tissue microarrays constructed from 679 NSCLC tumor tissues, including 392 cases in the discovery set and 287 cases in the validation cohort. We also studied clinicopathologic characteristics of these patients.

RESULTS

Overall, HHLA2 was not detected in most of normal lung tissue but expressed in 66% of NSCLC across different subtypes. In particular, EGFR-mutated NSCLC was significantly associated with higher tumor HHLA2 expression in both discovery (EGFR vs. WT: 76% vs. 53%, P = 0.01) and validation cohorts (89% vs. 69%, P = 0.01). In one of the two cohorts, HHLA2 expression was higher in lung adenocarcinoma as compared with squamous and large cell histology, non-Hispanic White versus Hispanics, and tumors with high tumor-infiltrating lymphocyte (TIL) density. In the multivariate analysis, EGFR mutation status and high TIL intensity were independently associated with HHLA2 expression in lung adenocarcinoma.

CONCLUSIONS

HHLA2 is widely expressed in NSCLC and is associated with EGFR mutation and high TILs in lung adenocarcinoma. It is potentially a novel target for lung cancer immunotherapy. Clin Cancer Res; 23(3); 825-32. ©2016 AACR.