PDCD1LG2 and renal carcinoma: Current major immunotherapies in cancer, including renal cancer, are based on the blocking by specific monoclonal antibodies of the binding of the B7 immune checkpoint proteins CD80/B7-1 and CD86/B7-2, and PD-L1/B7-H1 and PD-L2/B7-DC, with their co-receptors CTLA-4 and PD-1, respectively.