4-Chlorobenzo[f]isoquinoline

CBIQ is an activator of the cystic fibrosis transmembrane conductance regulator (CFTR) and the intermediate-conductance calcium-sensitive K+ channel (KCNN4). CBIQ is a novel tool for a new ion channel; first activator of ΔF508 CFTR, the mutant form of CFTR chloride channel present in 75% of cystic fibrosis patients. Other benzoquinolines act at the normal CFTR but not at ΔF508 CFTR. CBIQ also activates KCNN4, which hyperpolarizes airway epithelial cells to promote anion flux, a further benefit in cystic fibrosis.