Thus, differently from Bernstein et al.6and Mulloi et al.16in which large epithelial lesions and consequent increases in GM-CSF and IL-6 were respectively shown, for nasal polyps this study showed a wide range of normal values for such cytokines, suggesting greater epithelium integrity on NP in CF patients and a lesser participation of IL-6 and GM-CSF in this micro inflammatory environment. This evidence concerns the gene CSF2 and cystic fibrosis.