ITPR3 and neoplasm: Furthermore, Bcl-2 family proteins, which have pro- and anti-apoptotic functions, directly bind to different sites on IP3Rs and impact IP3R function, suggesting that IP3R is an important hub for the action of Bcl-2 family proteins in various physiological and pathological settings including tumor progression (Seo et al. 2015; Oakes et al. 2005; Letai 2008).