Of note, we validated the role of RAC1, an ERG, in modulating the behavior of melanoma cells and regulating the expression of programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) in vitro. Here, PDCD1 is linked to melanoma.