Compared with conventional therapy, ICI combination therapies have shown longer progression-free and overall survival in randomized clinical trials, such as PD-1/L1 inhibitor plus CTLA-4 inhibitor for advanced melanoma, renal cell carcinoma, and colorectal cancer (Wolchok et al., 2017; Motzer et al., 2018; Overman et al., 2018); the PD-1/L1 inhibitor combination for renal cell carcinoma (Rini et al., 2019); and the PD-1/L1 inhibitor and cytotoxic chemotherapy combination for non-small-cell lung cancer and triple-negative breast cancer (Gandhi et al., 2018; Schmid et al., 2018). The gene discussed is CTLA4; the disease is renal cell carcinoma.