Finally, to determine if BRCA1 partners involved in HR, NHEJ, and MMR may have a role in breast and ovarian cancer development, we performed a somatic mutational analysis by next generation sequencing (NGS) of MSH6, RAD50, MRE11A, and RAD51 genes in selected breast and/or ovarian tumors from BRCA1 missense variant carriers, BRCA1 mutation carriers, and BRCA1wt individuals. Here, MSH6 is linked to ovarian cancer.