SHIP1 is an inositol 5-phosphatase which is well established for its tumour suppressor potential in leukaemia. Enzymatically, two SHIP1 substrates, PtdIns(3,4,5)P-3 and Ins(1,3,4,5)P-4 have been identified to date. Additional substrates were found for the homologue SHIP2. In this study, we identified new inositol phosphate (InsP) substrates of SHIP1 by metal dye detection high-performance liquid chromatography and compared the substrate profiles of SHIP1 and SHIP2. We were able to verify Ins(1,3,4,5)P4 as a substrate of SHIP1 and interestingly found Ins(1,2,3,4,5)P-5 and Ins(2,3,4,5)P-4 to be preferably used as substrates and Ins(1,4,5,6)P-4 and Ins(2,4,5,6)P-4 to be weak substrates. All of those except Ins(2,3,4,5)P-4 are also known substrates of SHIP2 indicating a possible exclusive role of Ins(2,3,4,5)P-4 hydrolysis for SHIP1 but not SHIP2 function. (C) 2020 Published by Elsevier Inc.