ITPR1 and glioblastoma: Moreover, in view of the highly concentrated localization of the IP3R/Ca2+ channels in secretory granules of neuroendocrine cells [39] and of the key role of Ca2+ release through the IP3R/Ca2+ channels in proliferation, migration, and survival of glioblastoma [42], we have also examined the potential presence of the IP3Rs in the large dense core vesicles of astrocytes.