Inactivating mutations of AT-rich interactive domain-containing protein 1A (ARID1A) and Phosphatase and TENsin homolog deleted on chromosome 10 (PTEN); activating mutations of catenin β1 gene (CTNNB1), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) have been observed in endometrioid carcinomas [11,13,14,15,16]. Here, ARID1A is linked to endometrioid adenocarcinoma.