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]. This evidence concerns the gene MSH3 and breast cancer.