TNF and cystic fibrosis: While factors such as tumor necrosis factor-alpha (TNF-α) can prime exocytosis of neutrophil azurophilic granules (90), Forrest and colleagues observed GRIM reprogramming only upon stimulation with ex vivo CF samples but not with exogenously added chemokines, suggesting a yet unidentified factor in CF airways is responsible for changes in neutrophil activity (89).