PDCD1 and lung cancer: Candidate target antigens currently being studied in lung cancer and MPM clinical trials include overexpressed TAAs (Carcinoembryonic antigen, CEA; Disialoganglioside, GD2; Glypican-3, GPC3; Human epidermal growth factor 2, HER2; Mesothelin, MSLN; PD-1; Receptor tyrosine kinase-like orphan receptor, ROR1), novel gene products (Epidermal growth factor receptor, EGFR), the aberrant glycosylation (Mucin1, MUC1) that results from splice variants, and interstitial factors associated with the TME (Fibroblast activation protein, FAP; Vascular endothelial growth factor receptor 2, VEGFR2) [135].