USP2 and plasma cell myeloma: ML364 is a small molecule inhibitor of the deubiquitinase USP2, which could degrade CCND1 and prevent cancer cell cycle progression in colorectal cancer [26]; USP7 could induce apoptosis in multiple myeloma cells resistant to conventional and bortezomib therapies [27]; Developing the medicines based on the USPs are considered as a potential new treatment for cancer.