PDCD1LG2 and cancer: It is an immunotherapy drug from GlaxoSmithKline which is a humanized IgG4 monoclonal antibody that binds to and inhibits PD-1 protein on cancer cells while blocking checkpoint proteins found on T cells or cancer cells namely, programmed cell death receptor ligands 1 and 2 (PD- L1 and PD-L2), from binding with the receptor, restoring immunological function via activating T cells and therefore terminating cancer cells.