Programmed cell death protein 1 (PD-1) antibody was also approved for the treatment of advanced melanoma by FDA in the year of 2014 and phase 3 clinical trial of Relatlimab, targeting lymphocyte-activation gene 3 (LAG-3), has met its primary endpoint of PFS, which may offer new hope for SKCM patients in the future. Here, PDCD1 is linked to melanoma.