CFTR and cystic fibrosis: A 2020 study in Flanders evaluated the cost effectiveness of four NBS strategies for CF [IRT-DNA (immunoreactive trypsinogen, cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation analysis), IRT-PAP (pancreatitis-associated protein), IRT-PAP-DNA, and IRT-PAP-DNA-EGA (extended CFTR gene analysis)], assessing whether each met the guidelines of the European Cystic Fibrosis Society [726].