MRC1 and breast cancer: An analysis of mismatch repair (MMR) genes (traditionally linked to hereditary non-polyposis colorectal cancer) in a set of 34,981 cancer patients in a study by Espenschied et al. revealed that out of 528 patients with MMR mutations, 63 (11.9%) had breast cancer only and thus MSH6 and PMS2 mutation carriers may manifest with a hereditary breast and ovarian cancer phenotype [42].