There are currently over 2,100 variants in the CFTR gene recorded in the CF Mutation Database (http://www.genet.sickkids.on.ca/cftr/StatisticsPage.html), however F508del is by far the predominant mutation, present in ~80% of all individuals with CF worldwide (Cystic Fibrosis Foundation, 2020; Zolin et al, 2020). The gene discussed is CFTR; the disease is cystic fibrosis.