Cystic Fibrosis (CF) is the most common, fatal genetic mutation in the Australian population. It results in defective function of a crucial protein that leads to thick sticky mucus. This builds up in the lungs and other organs, causing recurring infections and eventually premature death. New medications that improve the working of this protein are about to become available. This proposal will collect blood, sputum and tissue from all the CF clinics in NSW, during the introduction of these drugs. Clinical data is already captured on a national data registry the Australian CF data registry. This will then be a powerful tool to better understand disease progression in CF and assess the impact of novel treatments and determine in whom they work best.