TNF and cystic fibrosis: Proteins, IL8 and TNF-α, play a crucial role in the pathophysiology of CF lung disease due to their participation in the recruitment and activation of neutrophils on the respiratory epithelial surface, which is a primary component of the innate immune response.11 Thus, genesCXCL8 andTNF coding for those cytokines, which expression is regulated by sequence variants, are highlighted as potential modifier genes in the severity of lung disease in CF.