However, it is now established that additional hereditary cancer predisposition syndromes are linked to an ever increasing number of genes, including but not limited to TP53, CDH1, SKT11, PTEN, PALB2, MLH1, MSH2, PMS1, PMS2, and MSH6, which have also been associated with increased risk of breast, ovarian, and other cancers, often as part of more complex family histories including colon, endometrial, gastric, brain, and/or other cancers (Rahman et al., 2007; Roberts et al., 2018; Schon and Tischkowitz, 2018). This evidence concerns the gene MLH1 and cancer.