USP1 and triple-negative breast carcinoma: On the other hand, LSD1 deubiquitination catalyzed by USP1 stabilized LSD1 protein in triple-negative breast cancer (TNBC) cells, and USP1 depletion led to decreased cellular LSD1 level, and led to pharmacological effects similar to LSD1 depletion, such as negatively affected cell proliferation, migration, invasion, sphere formation, and induced apoptosis [40].