Alterations in P2X7 receptor levels and function are believed to contribute to the pathogenesis of HD.A third category of organic cations, including calmidazolium and 1-[N,O-Bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpipera zine(KN-62) (at 10 nM), inhibits rP2X7R activation by blocking BzATP-induced currents. The gene discussed is P2RX7; the disease is Huntington disease.