USP22 and cancer: Besides OTUB1, other DUBs, such as USPs family (USP1, USP7, USP8, USP15, USP22) [57–67], OTUs family (OTUD7B, OTUD6B, A20, and OTUB2) [68–75] and other DUBs have been identified to regulate the progression of various cancers and applied for clinical cancer therapy.