Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), encoding the p110 subunit of class I PI3Ks, is highly activated and mutated in various human cancers, including the brain, liver, stomach, lung, and colon cancers (15, 18). The gene discussed is PIK3CA; the disease is colonic neoplasm.