Followed the classical single polymorphism approach, we have found no association between individual LT-α or TNF-α single SNPs and lung function in our CF cohort (Additional file 2: Table S2) but neutrophil elastase activity was higher in sputum specimens from carriers of genotypes TNF-α–308GA or LT-α + 252GG, associated with increased TNF-α production (Figure 1). This evidence concerns the gene TNF and cystic fibrosis.