Dr. Kelly A. Frazer, UC San Diego School of Medicine Cystic fibrosis is a disorder that mostly affects the lungs. It is caused by a mutation in a gene called cystic fibrosis transmembrane conductance regulator (CFTR). As a result of this mutation, cells that produce mucus (a slimy substance like the one in your nose) … Continue reading CIRM funded study may help explain why some people with cystic fibrosis are less prone to infection