The ability of P2Y2Rs to induce chloride secretion and subsequent fluid flow across epithelial cell membranes led to investigation of the P2Y2R as a therapeutic target for cystic fibrosis (Weisman et al., 1998; Kellerman et al., 2002; Lazarowski and Boucher, 2009). The gene discussed is P2RY2; the disease is cystic fibrosis.