IL17A and asthma: The imbalance of Th17/Treg has been reported to be mainly involved in asthma pathogenesis, including neutrophil recruitment and exacerbation of airway inflammation mediated by upregulated Th17-type cytokines (IL-17A, IL-17F, and IL-22) and downregulated Treg-type cytokines (IL-10, and transforming growth factor (TGF) -β) (Newcomb and Peebles, 2013; Boonpiyathad et al., 2020).