It has been shown that they have more frequent mutations in Phosphatase and Tensin Homolog (PTEN), Catenin Beta 1 (CTNNB1), AT-Rich Interaction Domain 1A (ARID1A), ARID5B, and KRAS. Comparatively, Group 4, comprising 94% of uterine serous carcinomas (USCs), which represent the most aggressive histologic type, and 12% of endometrial adenocarcinomas, demonstrated extensive copy number alterations of the oncogenes MYC, Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2) and cyclin E1 (CCNE1), and frequent TP53 mutations [7]. Here, ARID1A is linked to endometrial serous adenocarcinoma.