Cystic fibrosis is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. These mutations cause the CFTR protein to become dysfunctional, which prevents the movement of chloride to the cell surface. Without chloride, water is not attracted to the cell surface, and mucus in various organs becomes thick and sticky. In the lungs, the thick mucus clogs the airways and traps germs, leading to infections, inflammation, respiratory failure, and other complications. In the pancreas, the buildup of mucus prevents the release of digestive enzymes that help the body absorb food and key nutrients, resulting in malnutrition and poor growth. In the liver, the thick mucus can block the bile duct, causing liver disease. Cystic fibrosis is a genetic (inherited) disease, and people who have CF inherit two faulty genes, one from each parent.