BRCA1 and breast cancer: BRCA1/2 proteins participate mainly in the HR repair (HRR) pathway, and mutations in their genes are associated with elevated susceptibility to the development of ovarian cancer (40–60% and 11–30% for BRCA1and BRCA2, respectively), breast cancer (72% and 69%, respectively; especially BRCA1 (17q21) and BRCA2 (13q13)), prostate cancer (1% and 11.4% for BRCA1 and BRCA2, respectively) and pancreatic cancer (uncertain rate, BRCA2 > BRCA1) [6–8].