Cystic fibrosis is the most common human genetic disease; anion secretion is severely decreased due to mutations in the Cftr gene affecting mainly airway function, but an important number of patients are also affected by intestinal problems with mucus attachment and obstruction (Gustafsson et al., 2012; De Lisle and Borowitz, 2013). The gene discussed is CFTR; the disease is cystic fibrosis.