For example, it is observed that the expression of miR‐126 is obviously increased in the airway of mouse asthma models sensitized by house dust mite (HDM); considering that the main sensitizing component of HDM is toll‐like receptor 4 (TLR4) signaling pathway that activates lipolysaccharides in the immune inflammatory response, the TLR4 is then knocked out, which disclosed that no significant change in the expression of miR‐126 in HDM sensitized mice, suggesting that miR‐126 may be involved in the pathological process of asthma through upregulation of TLR4.12 Here, TLR4 is linked to asthma.