Among the best known and characterised proteins are breast cancer susceptibility type 1 and 2 (BRCA1 and BRCA2), ataxia-telangiectasia mutated (ATM), the MRN complex (consisting of meiotic recombination 11 [MRE11], RecA-like protein 50 [RAD50] and Nijmegen breakage syndrome protein 1 [NBS1]), and RAD51 (Fuh et al., 2020). The gene discussed is ATM; the disease is breast carcinoma.