The possible causative link between melanoma and BP is still debated and the putative pathogenetic mechanism is the result of some speculations: i) antibodies produced against tumor-specific antigens, also as a consequence of the expression of BP antigens on transformed melanocytes, might cross-react or react with the basement membrane zone antigens inducing BP onset; ii) the appearance of BP following anti-PD1/PDL-1 therapy, likely due to an immune response targeting melanoma that spreads towards an autoreactive response to BP antigens (Figure 1). Here, PDCD1 is linked to melanoma.