This gene encodes a member of the inositol phosphokinase family. The encoded protein has 3-kinase, 5-kinase and 6-kinase activities on phosphorylated inositol substrates. The encoded protein plays an important role in the biosynthesis of inositol 1,3,4,5,6-pentakisphosphate, and has a preferred 5-kinase activity. This gene may play a role in nuclear mRNA export. Pseudogenes of this gene are located on the long arm of chromosome 13 and the short arm of chromosome 19. [provided by RefSeq, Dec 2010].