A previous study showed that ATR inhibition decreased the expression of PD-L1 by destabilizing PD-L1 in a proteasome-dependent manner to attenuate PD-1/PD-L1 interaction and sensitized cancer cells to T cell killing, which provided a rationale for the combination therapy of ATR inhibitors with other types of ICIs, such as anti-CTLA-4 or anti-TIM-3 (85). Here, ATR is linked to cancer.