PDCD1 and non-small cell lung carcinoma: In lung cancer, ICIs targeting the PD-1/PD-L1 pathway have shown limited success in patients with NSCLC that harbored activating EGFR mutations, because activated EGFR signaling allows NSCLC cells to use multiple strategies to create an immunosuppressive TME, including recruitment of TAMs and Tregs, and at the same time, produce inhibitory cytokines and metabolites [89].