CFTR occurs in the upper and lower respiratory tract and also in mucous membranes in the intestine. The effects of CFTR mutations and drugs can be different between these different tissues. In this project we study CFTR and the effects of medication in different tissues of the same person. In the laboratory miniature small arms are grown from intestinal tissue, and properties in the mini-arms are compared with airway tissue from the lungs and the nose that is grown in the lab. In addition, new ways of studying CFTR function are being developed using airway tissues.