CD8A and neoplasm: Studies have shown that Programmed Death ligand-1 (PD-1) is highly expressed in CD8+T cells in cSCC and blocking PD-1 with monoclonal antibody is one of the effective methods.11, 12 PD-1 inhibitors can block the binding of PD-1 and PD-L1, resulting in the transduction of immunosuppressive signals in the PD-1/PD-L1 pathway, and then restore and promote the immune killing function of CD8+T cells,10, 13 making them play a powerful anti-tumor role.