In human ADPKD cells, elevated intracellular cAMP activates cystic fibrosis transmembrane conductance regulator (CFTR)-mediated Cl− secretion and B-Raf/MEK/ERK signaling, causing fluid secretion and increased proliferation of cyst-lining epithelial cells, respectively38,39. Here, CFTR is linked to autosomal dominant polycystic kidney disease.