Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is an oncogene that positively regulates the PI3K, Akt/mTOR signaling pathway, and the activation of this signaling pathway is involved in the progression of many malignancies, such as colon, breast, lung, and lymphoma. The gene discussed is PIK3CA; the disease is lymphoma.