ELISAs using CCM collected from submerged primary human CF HBE cells (obtained from three CF donors) confirmed the ability of TNF-α to stimulate IL-8, IL-6, CXCL1 and GM-CSF, an effect that was significantly reduced by ETI (38%, 45%, 49% and 65%, respectively) (figure 4a–d). This evidence concerns the gene CSF2 and cystic fibrosis.