This antibody is tested in Peptide ELISA: antibody detection limit dilution 128,000. Inositol 1, 4, 5-trisphosphate 3-kinase (ITPK) catalyzes the phosphorylation of Ins(1, 4, 5)P3 to Ins(1, 3, 4, 5)P4, both of which are modulators of calcium homeostasis.