Cyclic nucleotide–mediated (cAMP- or cGMP-mediated) CFTR activation and consequent Cl– secretion represent the key pathology in certain secretory diarrheas including cholera, and traveler’s diarrhea and diarrhea caused by vasoactive intestinal peptide–secreting (VIP-secreting) tumors (VIPomas) (5, 6, 34). The gene discussed is CFTR; the disease is vibrio infectious disease.