EZH2 and colorectal cancer: Consistently, the proteasome inhibitor MG‐132 and PSI were able to upregulate the expression of PD‐L1 in colorectal cancer, but not lysosome or autophagy inhibitor (Figure 2D; Figure S2D, Supporting Information), suggesting that EZH2 inhibition may primarily enhance PD‐L1 protein stability through its influence on the ubiquitin‐proteasome pathway, specifically in a proteasome‐dependent manner.