CSF3 and asthma: The mechanism of airway neutrophilia in severe asthma is not known; IL-17 appears to play an important role in neutrophilic inflammation, which induces the production of chemokines and cytokines (such as G-CSF, GM-CSF, CXCL1, CXCL6, CXCL8, CSF3, IL-6, and IL-8) by bronchial epithelial cells to elicit neutrophilic airway inflammation [62–64].