PDCD1 and metastatic melanoma: In a further study, 177 patients affected by metastatic melanoma were evaluated prospectively after treatment with ipilimumab (n = 15), anti–PD–1 (nivolumab, pembrolizumab) (n = 103), or combined ipilimumab and anti–PD–1 (n = 59) [91], and the development of irAEs was investigated.