CF is a monogenic disorder caused by biallelic germline mutations in the CF transmembrane conductance regulator (CFTR/ABCC7; MIM #602421) gene, involved in transmembrane chloride and bicarbonate transport in epithelial cells, mainly affecting lungs, digestive tract, sweat glands and vas deferens in men. The gene discussed is CFTR; the disease is cystic fibrosis.