. "Reviewed: Gotoh, N, 2011-08-26"^^ . "Authored: Rothfels, K, 2011-08-15"^^ . "The 110 kDa catalytic subunit (PIK3CA) binds to the 85 kDa regulatory subunit (PIK3R1) to create the active PIK3."^^ . . . . . . . "PI3K catalytic subunit binds to GRB2:GAB1:PI3Kreg (indirect)"^^ . . . .