CFTR and cystic fibrosis: Its role in CF lung tissue damage has been further increased by its effect on degradation of CFTR protein (32), which can potentially reduce the efficacy of novel CFTR modulators, and by the evidence that its expression is upregulated by the pro-inflammatory cytokine TNF-alpha (TNF-α) and the chemokine interleukin (IL)-8 (or CXCL8) in CF lung (33).