Increased risk for endometrial cancer development is associated in less extend with: (i) Lynch syndrome (2–6% of ECs) caused by monoallelic germline mutation in MLH1, MSH2, MSH6, or PMS2 mismatch repair genes (8), (ii) polymerase proofreading-associated polyposis attributed to germline mutations of the DNA polymerase-delta 1 (POLD1) or DNA polymerase-epsilon (POLE) (9), and Cowden syndrome caused by tumor suppressor PTEN mutations (10). This evidence concerns the gene MLH1 and endometrial cancer.