The overall survival of advanced-stage melanoma patients has improved dramatically in the last 5 years with development of immunotherapy by monoclonal antibodies blocking cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell-death protein 1 (PD-1) and with application of B-Raf or MEK kinase inhibitors in BRAF gene mutant tumours [33]. The gene discussed is PDCD1; the disease is melanoma.