PDCD1 and mucosal melanoma: In a multi-institutional retrospective cohort analysis of 35 patients with mucosal melanoma receiving anti-PD-1 therapy (nivolumab or pembrolizumab) after pretreatment with ipilimumab, an ORR of 23% (95% CI 10–40%) and a median progression-free survival (PFS) of 3.9 months after a median follow up of 10.6 months were reported [24].