Studies in vitro conducted in the human astrocytoma cell line U87, and in primary cultures of rat microglia and oligodendroglia showed that CaSR stimulates Ca2+-activated K+ channels, thus contributing to local ionic homeostasis following the lowering of [Ca2+]o due to increased neuronal activity; there are also indications that CaSR could also play a role in microglia activation (Chattopadhyay et al., 1998, 1999a,b). Here, CASR is linked to astrocytoma (excluding glioblastoma).