CFTR and cystic fibrosis: The relationship between the cystic fibrosis transmembrane conductance regulator gene (CFTR, OMIM: 602421) and CF is well‐established (Zielenski & Tsui, 1995), with over 2000 CFTR variants identified, as curated by the Cystic Fibrosis Variations Database (https://www.genet.sickkids.on.ca/cftr/app).