磷脂酰肌醇3-激酶（PI3K）是一种脂质激酶，能磷酸化磷脂酰肌醇和类似化合物，在生长信号传导途径中产生重要的第二信使。PI3K作为调节亚单位和催化亚单位的异二聚体发挥作用。该基因编码的蛋白质是PI3K的调节成分，已发现该基因有两个转录变体，一个蛋白编码，另一个非蛋白编码。
Phosphatidylinositol 3-kinase (PI3K) is a lipid kinase that phosphorylates phosphatidylinositol and similar compounds, creating second messengers important in growth signaling pathways. PI3K functions as a heterodimer of a regulatory and a catalytic subunit. The protein encoded by this gene is a regulatory component of PI3K. Two transcript variants, one protein coding and the other non-protein coding, have been found for this gene.