ITPR3 and neuroblastoma: These cells are derived from a human neuroblastoma; they exhibit many neuronal characteristics (Agholme et al., 2010); they express M3 muscarinic acetylcholine receptors that evoke IP3-mediated Ca2+ release and SOCE (Grudt et al., 1996); and they express predominantly IP3R1 (Wojcikiewicz, 1995; Tovey et al., 2001), with detectable IP3R3, but no IP3R2 (Figure 2A).