Supplementation of oral NAC was linked to significantly increased blood glutathione levels and decreased neutrophils, IL-8, and elastase activity in sputum of CF patients (Tirouvanziam et al., 2006) A randomized double-blind placebo-controlled trial including 70 CF patients for 24 weeks showed stability or a slight increase in spirometric lung function in NAC treated participants compared to the control group (Conrad et al., 2015). The gene discussed is CXCL8; the disease is cystic fibrosis.