Previous studies have found that due to its key role in barrier immunity and its synergistic effects with other cytokines, such as TNF-α, IFN-γ, and IL-1, IL-17 plays an important role in many skin diseases (16), allergic diseases such as allergic rhinitis (17) and asthma (18), and inflammatory bowel disease (19, 20). Here, IL17A is linked to asthma.