Immunotherapies, particularly immune checkpoint inhibitors (ICIs), that target programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling pathway, have prompted a paradigm shift in cancer treatment, demonstrating significant efficacy and long-term clinical benefits in different cancers, particularly melanoma and NSCLC (4, 5). The gene discussed is PDCD1; the disease is melanoma.