CFTR and cystic fibrosis: Cystic fibrosis (CF; OMIM: no. 219700), one of the most common Mendelian autosomal recessive disorders, is characterized by two aberrant copies of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR; region 7q31.2) gene [1], which ultimately alter the CFTR protein, an ion channel responsible for transporting chloride and bicarbonate across epithelial surfaces, leading to the dysregulation of endothelial cells and decreased pH in airway surface liquid [1,2,3].