group gene protein aliases EC number class 1 catalytic PIK3CA PI3K, catalytic, alpha polypeptide p110-α 2.7.1.153 PIK3CB PI3K, catalytic, beta polypeptide p110-β PIK3CG PI3K, catalytic, gamma polypeptide p110-γ PIK3CD PI3K, catalytic, delta polypeptide p110-δ class 1 regulatory PIK3R1 PI3K, regulatory subunit 1 (alpha) p85-α N/A PIK3R2 PI3K, regulatory subunit 2 (beta) p85-β PIK3R3 PI3K, regulatory subunit 3 (gamma) p55-γ PIK3R4 PI3K, regulatory subunit 4 p150 PIK3R5 PI3K, regulatory subunit 5 p101 PIK3R6 PI3K, regulatory subunit 6 p87 class 2 PIK3C2A PI3K, class 2, alpha polypeptide PI3K-C2α 2.7.1.154 PIK3C2B PI3K, class 2, beta polypeptide PI3K-C2β PIK3C2G PI3K, class 2, gamma polypeptide PI3K-C2γ class 3 PIK3C3 PI3K, class 3 Vps34 2.7.1.137