PDCD1 and melanoma: Anti–PD-1/PD-L1 pathway therapy has been identified as safe in several advanced cancers including melanoma and NSCLC, and a systematic meta-analysis revealed that PD-1/PD-L1 inhibitor was in lower risk and better tolerated by comparing incidences of all and high-grade adverse events (AEs) between the PD-1/PD-L1 inhibitors group and the chemotherapy group (92).