PDCD1 and obesity due to melanocortin 4 receptor deficiency: Although AM and MM fundamentally differ from nonacral CM in their pathogenesis and therapeutic targets,27 further studies should include investigation of mechanisms other than mutational burden that can be influenced extrinsically, including factors such as obesity and differential composition of the gut microbiome, for their potential contribution to differential immune responses and efficacy of anti‐PD‐1 in these rare melanoma subtypes.