Monocytes from healthy controls and from CFTR modulator-naïve, clinically stable patients with CF having at least one copy of the F508del CFTR mutation (individuals were either homozygous for F508del or heterozygous with a class I stop mutation; table S1) were isolated and cultured for 7 days in the presence of macrophage colony-stimulating factor (M-CSF; CSF1) to generate MDMs. This evidence concerns the gene CFTR and cystic fibrosis.