4-bisphosphate 4-phosphatase, Inositol polyphosphate 4 phosphatase type II 105kDa, Inositol polyphosphate 4-phosphatase type II, Inpp4b, MGC132014, Type II inositol 3,4 bisphosphate 4 phosphatase, Type II inositol-3.
Catalyzes the hydrolysis of the 4-position phosphate of phosphatidylinositol 3,4-bisphosphate, inositol 1,3,4-trisphosphate and inositol 3,4-trisphosphate. Plays a role in the late stages of macropinocytosis by dephosphorylating phosphatidylinositol 3,4-bisphosphate in membrane ruffles.The lipid phosphatase activity is critical for tumor suppressor function. Antagonizes the PI3K-AKT/PKB signaling pathway by dephosphorylating phosphoinositides and thereby modulating cell cycle progression and cell survival