USP5 and neoplasm: To further explore the role of USP5 in regulating T cell function and tumor growth in vivo, Usp5 cKO (Usp5flox/floxCd4-Cre) mice with specifically deleting Usp5 in T cells were generated through crossing Usp5flox/flox mice with Cd4-Cre mice (Fig. 5a, b).