P32019. Hydrolyzes PtIns(4,5)P2 and the signaling molecule phosphatidylinositol 1,4,5-trisphosphate [PtIns(1,4,5)P3], and thereby modulates cellular signaling events. The inositol polyphosphate 5-phosphatase INPP5B is a gene paralog of the Lowe syndrome OCRL1, sharing similar substrate specificity, domain organization, and an ability to partially compensate for loss of OCRL1 in knockout mice. Here, INPP5B is linked to oculocerebrorenal syndrome.