磷脂酰肌醇3-激酶（PI3K）是一種脂質激酶，能磷酸化磷脂酰肌醇和類似化合物，在生長信號傳導途徑中產生重要的第二信使。PI3K作為調節亞單位和催化亞單位的異二聚體發揮作用。該基因編碼的蛋白質是PI3K的調節成分，已發現該基因有兩個轉錄變體，一個蛋白編碼，另一個非蛋白編碼。
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.