Analogous with CTLA-4, there have been few studies on the regulation by circRNAs of other newly discovered immune checkpoints in recent years, such as TIM-3, SIRPα and CD47, which may be due to the fact that the mechanism of these immune checkpoints is not yet fully elucidated, and the exploration of ICIs targeting them as cancer immunotherapy is still at an early stage. Here, CTLA4 is linked to cancer.