PIK3CA and endometrium adenocarcinoma: Analyses revealed that the tumors not only harbored mutations characteristic of sarcoma, such as RB1 (50%), ATRX (38%), and FBXW7 (17%) mutations, but also possessed mutations commonly associated with endometrial adenocarcinoma, including PTEN (42%), PIK3CA (42%), and AKT (17%) mutations.