Inositol Monophosphatase 1 (IMPA1) belongs to the inositol monophosphatase family. IMPA1 is responsible for the provision of inositol required for synthesis of phosphatidylinositol and polyphosphoinositides, IMPA1 can use myo-inositol-1,3-diphosphate, myo-inositol-1,4-diphosphate, scyllo-inositol-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-phosphate, beta-glycerophosphate, and 2-AMP as substrates. IMPA1 has been implicated as the pharmacological target for lithium action in brain. IMPA1 shows magnesium-dependent phosphatase activity and is inhibited by therapeutic concentrations of lithium. In addition, IMPA1 plays a improtant role in intracellular signal transduction.