Cystic fibrosis is a severe genetic disorder caused by a single gene called the cystic fibrosis transmembrane regulator (CFTR). The disease is characterized by chronic and persistent respiratory infections, which progressively damage and eventually destroy lung function. Research has shown that cystic fibrosis patients with the same alteration in the CFTR gene may each follow a very different clinical course: with one patient having very mild lung disease and infrequent lung infections, while another will have frequent lung infections and significantly decreased lung function. Dr. Andrew Sandford is investigating genes other the CFTR gene that may play a role in causing lung disease to progress more quickly in some cystic fibrosis patients than in others. It is thought that cystic fibrosis patients may also have compromised immune function. For this reason, Dr. Sandford is looking for genes involved in fighting infections and in controlling the inflammatory response to the bacteria and viruses that attack the lungs.