PDCD1 and non-small cell lung carcinoma: A retrospective and multicentre study was designed, which involved a total of 251 patients affected by different tumors (mostly non-small cell lung cancer, 68.92% and melanoma, 24.30%) and treated with the PD-1 inhibitors nivolumab (61.35%) or pembrolizumab (38.65%) for up to 60 months.