PDCD1 and cancer: Indeed, LAG-3 and PD-1 are commonly co-expressed on exhausted or dysfunctional T cells in models of chronic infections and cancers (72), the coordinated inhibition of LAG-3 and PD-1 can enhance the immune response, Therefore, most of the current clinical trials on LAG-3 antibodies are combined with PD-1 to observe the effect (73–75).