USP22 and lung cancer: Although USP7, USP22 and OTUB1 played a certain role in the regulation of PD-L1 in NCI-H358 cells and USP22 slightly regulated PD-L1 abundance in SK-MES-1 cells, we found that OTUB2 had the most significant impact on the regulation of PD-L1 both in NCI-H358 and SK-MES-1 lung cancer cells (Fig. 3g and Supplementary Fig. 10a−g).