RB1 and neoplasm: BRCA1 also interacts with numerous proteins to form complexes that are involved in SSB repair pathways and NHEJ, including tumor suppressors (BRCA2, p53, Rb and ATM), oncogenes (c-Myc, casein kinase II and E2F) and DNA damage repair proteins (RAD50, RAD51, MNS, Ku80 and CtIP) [45].