(CF) An incurable genetic disease involving a sticky buildup of mucus in the lungs (which makes breathing difficult and leads to infections), as well as pancreatic insufficiency (which leads to digestive problems). Symptoms include chronic cough producing thick mucus, excessive appetite combined with weight loss, intestinal disorders, salty sweat/skin and pneumonia. Lung-related problems are the most frequent cause of death. CF is a recessive disease, occurring only when a person inherits two mutated copies of the CF gene – one from each parent. Individuals with CF generally have a life expectancy of about 30 years.