Interestingly, while CFTR genotype correlates well globally with the pancreatic phenotype, it mostly fails to predict pulmonary-disease severity (Burke et al., 1992; The Cystic Fibrosis Genotype-Phenotype Consortium, 1993; Kerem and Kerem, 1996; Duguépéroux and De Braekeleer, 2004; Cutting, 2015; Raynal and Corvol, 2020). The gene discussed is CFTR; the disease is cystic fibrosis.