FAS and cystic fibrosis: Recently, it has been shown that neutrophils are eliminated by FAS/CD95 during viral and bacterial infections.4 However, neutrophils are also susceptible to other death receptors, in particular tumor necrosis factor receptor-1 (TNF-R1).5, 6, 7 Defects in the intrinsic (mitochondrial) apoptotic pathway prolong the lifespan of neutrophils.8, 9 Failure of neutrophils to undergo apoptosis contributes to chronic inflammation and tissue destruction and is found in various pathologies, such as rheumatoid arthritis, cystic fibrosis and chronic obstructive pulmonary disease.10, 11, 12