The function of Ensembl gene identifier ENSG00000143772 (ITPKB, inositol-trisphosphate 3-kinase B) is as follows. Catalyzes the phosphorylation of 1D-myo-inositol 1,4,5- trisphosphate (InsP3) into 1D-myo-inositol 1,3,4,5-tetrakisphosphate and participates to the regulation of calcium homeostasis. {ECO:0000269|PubMed:11846419, ECO:0000269|PubMed:12747803, ECO:0000269|PubMed:1654894}.