For instance, both high infiltration of PD-1+ CD8+ T effector cells and PD-L1+ CD25+ CD4 TILs in the TME showed more effectiveness for PD-1/PD-L1 blockade immunotherapy (12), while a poor clinical efficacy of PD-1 inhibitors was observed in EGFR+ or ALK+ patients who possessed a non-inflamed TME or a so-called cold tumor, i.e., a paucity of TILs and an influx of immunosuppressive cells (13, 14). The gene discussed is PDCD1; the disease is neoplasm.