Observed decrease of IL-17A expression level probably occurs because of lesions in mono-nuclear blood cells of mild and severe asthmatic individuals; these cells aberrantly expressed IL-17 which consequently triggers production of IL-6, IL-8, Granulocyte-Colony Stimulating Factor (G-csf), CXCL1 and Macrophage Inflammatory Protein which their elevation was reported in sera of individuals with asthma (38,39). Here, CXCL1 is linked to asthma.