PIK3CA and cancer: These tumors are frequently characterized by gene mutations that drive endometroid cancer pathogenesis, including phosphatase and tensin homolog (PTEN), Kirsten rat sarcoma viral oncogene (KRAS), adenine thymine-rich interactive domain 1A (ARID1A), and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA).