IL4 and asthma: For the HDM-induced asthma mouse model, ILC2-deficient mice showed a decrease in eosinophils in BALF and a decrease in lung ILC2s; both total serum IgE and HDM antigen-specific IgE and IgG1 levels were significantly reduced, and the expression of lung transcripts of IL-4 and IL-5 was significantly reduced compared to that of WT mice.