Melanoma is frequently characterized by high PDL-1 expression, and different antibodies blocking the PD-1/PDL-1 axis, such as nivolumab (BMS-936558, MDX-1106) and pembrolizumab (MK-3475), have been approved for its treatment (Francisco et al., 2010; Hino et al., 2010; Pardoll, 2012; Sunshine and Taube, 2015; Li et al., 2016). This evidence concerns the gene PDCD1 and melanoma.