This gene encodes a member of the inositol phosphokinase family. The encoded protein may be responsible for the conversion of inositol hexakisphosphate (InsP6) to diphosphoinositol pentakisphosphate (InsP7/PP-InsP5). It may also convert 1,3,4,5,6-pentakisphosphate (InsP5) to PP-InsP4. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jun 2011].