CF ferrets are also rarely used, since they develop severe airway infections soon after birth and subsequently succumb to respiratory failure (Hoffman and Hajjar, 2018;Sunet al., 2010), although this situation may change asin utero administration of cystic fibrosis transmembrane conductance regulator (CFTR) modulators can rescue this severe phenotype (Sunet al., 2019). The gene discussed is CFTR; the disease is respiratory failure.