PDCD1 and neoplasm: Immune checkpoint inhibitors (ICIs) can promote the immune-mediated killing of tumor cells by activating T cells,[53] and these ICIs include anti-programmed cell death-1 (nivolumab and pembrolizumab), anti-programmed cell death ligand-1 (bavencio and tecentriq), and anti-cytotoxic T-lymphocyte antigen-4 (ipilimumab).