PIK3CA and uterine carcinosarcoma: Frequently found somatic mutations in uterine carcinosarcomas were present in TP53 and genes involved in the PI3K/Akt/mTOR pathway, such as PIK3CA, PTEN, and PIK3R1. Other significantly but less frequently mutated genes were FBXW7, PPP2R1A, KRAS, and ARID1A [37, 38].