Inositol polyphosphate 5-phosphatase OCRL-1 (INPP5F/OCRL) is also called Lowe oculocerebrorenal syndrome protein. INPP5F is a phosphotase that converts phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol 4-phosphate, as well as inositol 1,4,5-trisphosphate to inositol 1,4-bisphosphate and inositol 1,3,4,5-tetrakisphosphate to inositol 1,3,4-trisphosphate. ORCL is involved in primary cilia assembly and may also have a role in lysosomal membrane trafficking. ORCL is expressed in brain, skeletal muscle, heart, kidney, lung, placenta, fibroblasts, retina and the retinal pigment epithelium. INPP5F defects can cause Lowe oculocerebrorenal syndrome (OCRL) and Dent disease type 2 (DD2).