Possible mechanisms could be the poor antigenicity of tumors due to a low tumor mutation burden and the immunosuppressive microenvironment in tumor tissues; however, the reasons why PD-1/PD-L1 blockade therapies failed to show a survival benefit in EGFR-mutated NSCLCs are not fully understood [8, 24, 25]. This evidence concerns the gene PDCD1 and neoplasm.