P2RY1 and astrocytoma (excluding glioblastoma): Purinergic receptors express the distinctive feature that on stimulation of many of the P2Y subtypes, they respond by causing a quick change in signals of intracellular [Ca+2] which is useful for the screening of agonist and antagonist of purinergic receptors by performing calcium flux assay in P2Y transfected 1321N1 astrocytoma cell line (Govindan and Taylor, 2012).