Follow up studies revealed that the kidney secretin receptor (Scrt) in the collecting duct is dysregulated in CF mice (5, 6), thus impairing the signal between the secretin secretion from the small intestine to a change in function of the kidney collecting ducts; and therefore, hampering the ability of the kidney to eliminate excess HCO3- (5–7). The gene discussed is SCRT1; the disease is cystic fibrosis.