The function of INPP5J (inositol polyphosphate-5-phosphatase J, Ensembl gene identifier ENSG00000185133) is as follows. Inositol 5-phosphatase, which converts inositol 1,4,5- trisphosphate to inositol 1,4-bisphosphate. Also converts phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol 4- phosphate and inositol 1,3,4,5-tetrakisphosphate to inositol 1,3,4- trisphosphate in vitro. May be involved in modulation of the function of inositol and phosphatidylinositol polyphosphate-binding proteins that are present at membranes ruffles. .