The CF Mutation Database (http://www.genet.sickkids.on.ca) currently lists more than 2,000 mutations in the CFTR, but only a small number of them are clearly defined as CF‐causing based on epidemiological data and functional studies (http://www.cftr2.org) (Sosnay et al., 2013). Here, CFTR is linked to cystic fibrosis.