BRCA1 and cancer: GAs in HR genes, other than those in BRCA1/2, have been identified in many cancers, and preclinical studies suggest that specific HR GAs confer sensitivity to inhibitors of other DDR genes, such as ataxia-telangiectasia mutated (ATM), ataxia-telangiectasia and RAD3-related (ATR) and DNA-dependent protein kinase9.