MSH6 and breast cancer: MSH2 mutations have been associated with an increased risk of developing several tumors including colon, breast, ovarian, and endometrial cancers [44], however these mutations in breast cancer are quite rare, while amplifications are more frequent with 1% of cases showing overlapping amplification of MSH6 and MSH2 and up to 1.5% PMS2 amplification in other cases from METABRIC database (Fig. 3A).