BRCA1 and cancer: BRCA1 functions as a tumor suppressor, which is essential for the maintenance of genome integrity and suppression of malignant neoplasms.60 Although several E3 ubiqitinating enzymes have been documented to regulate BRCA1 ubiquitination and degradation,15, 16, 17, 18 no specific DUBs are known to control BRCA1 protein stability.