TPC2-A1-N is a powerful and Ca2+-permeable agonist of two pore channel 2 (TPC2), which plays its role by mimicking the physiological actions of NAADP. TPC2-A1-P reproducibly evokes significant Ca2+ responses from TPC2 (EC50=7.8 μM), and the effect can be blocked by several TPC blockers. TPC2-A1-N can be used to probe different functions of TPC2 channels in intact cells.