DNA repair genes, including ATM, ATR, BLM, CHD8, MSH2, MSH3, MSH6, PMS2, RAD54L, RECQL, SLX4 (FANCP), WRN, and XRCC3, which play important roles in homologous recombination DNA repair, maintenance of genomic integrity, and cell cycle regulation, are considered potential BC genes [55,56,57,58]. The gene discussed is ATR; the disease is breast cancer.