Severe forms of asthma have been associated with mixed granulocytes or neutrophilic inflammation accompanied by T helper 17 (TH17) cells and its associated cytokines [IL-17A, IL-6, granulocyte colony stimulating factor (G-CSF), tumour necrosis factor α (TNF-α), and C-X-C motif ligand 8 (CXCL8)] (39). This evidence concerns the gene IL17A and asthma.