Degradation of BRCA1 is also mediated by the proteasome after HERC2 (HECT-type E3 ligase) targeting; BRCA1, together with its partner BARD1 (BRCA1-associated RING domain 1), have an important role in HR and loss of any of these proteins results in susceptibility to breast cancer [178]. Here, BARD1 is linked to breast cancer.