ITPR1 and glioma: At micromolar concentrations, paxilline does however inhibit Ca2+-activated Cl- channels [29], inositol 1,4,5-trisphosphate receptors [30] and the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) [31], as well as stimulating glioma cell apoptosis independently of BKCa or SERCA inhibition [32].