Historically, asthma has been termed a T-helper cell type 2 (Th2)-driven disease characterized by reversible airway obstruction, thickened airway smooth muscle cells, subepithelial fibrosis, and a characteristic aberrant immune regulation with a predominance of Th2 cells secreting cytokines IL-4, IL-5, and IL-13 (42). Here, IL13 is linked to asthma.