RAD51 and cancer: Although the increased protein levels of RAD51 correlate with HR repair activity and radioresistance of cancer cells, recent study proposed that timely removal of RAD51 from damaged DNA ends through E3 ligase RFWD3-mediated ubiquitin-proteasomal degradation can facilitate the loading of other repair members, such as MCM8, onto chromatin, which is essential for HR repair [25].