IL4 and asthma: Through the study of asthmatic children and an OVA-induced murine asthma model, Zhou et al. [46] found that miR-221 overexpression could stimulate mast cells to secrete IL-4 by targeting PTEN, p38, and nuclear factor‐kappa B (NF-κB) signaling pathways, and subsequently promote the transformation of Th cells into Th2 cells.