CCG-63808 ((2E)-2-(1,3-benzothiazol-2-yl)-3-[9-methyl-2-(3-methylphenoxy)-4-oxo-4H-pyrido[1,2-a]pyrimidin-3-yl]prop-2-enenitrile) is a potent reversible inhibitor of regulator of G-protein signaling (RGS) proteins. Its mechanism seems to, at least in part, involve an allosteric action at the B site on the RGS which has been implicated in the physiological allosteric modulation of RGS proteins by acidic phospholipids and calmodulin. Regulators of G protein signaling (RGS) are major determinants of metabotropic receptor activity, reducing the lifespan of the GTP-bound state of G proteins. Inhibition of spinal RGS4 restored endogenous analgesic signaling pathways and mitigated neuropathic pain. Signalling through CB1 receptors may be involved in this beneficial effect.