Endometrioid ovarian carcinomas show broad morphological similarities to their endometrial counterparts with the most common molecular alterations in endometrioid OC including mutations in CTNNB1 (31–53.3%), PIK3CA (15–40%), ARID1A (30%), and PPP2R1A (7–16.6%) [39,41,42]. Here, ARID1A is linked to ovarian carcinoma.