CTLA4 and cancer: As targeted programmed death-ligand 1 (PD-L1), programmed death 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4), the existed ICB treatment has significantly improved the overall survival (OS) of patients in several cancers (Larkin et al., 2015; Motzer et al., 2015; Bellmunt et al., 2017).