So far, several monoclonal antibodies, blocking the interaction of PD-1 and PD-L1, such as Nivolumab, Pembrolizumab, and Tislelizumab, et al can reverse immunosuppressive conditions and improve the killing of tumor cells by host’s immune cells (tumor-specific CD8+ T cells) (Han et al, 2020), and are used to treat advanced melanoma, non-small cell lung cancer, and head and neck squamous cell cancer (Kraehenbuehl et al, 2022). Here, PDCD1 is linked to melanoma.