In PIK3CA, we identified p.T957 co-clustering with the highly recurrent p.H1047R that affects many gynecologic cancer cases, including 13.8% of breast invasive carcinoma (BRCA), 7% of uterine carcinosarcoma (UCS), and 5.8% of uterine corpus endometrial carcinoma (UCEC). Here, PIK3CA is linked to uterine corpus endometrial carcinoma.