TSLP and allergic asthma: In addition to inducing a Type 2 response through the stimulation of DC maturation, epithelial‐derived cytokines (IL‐33, IL‐25, and TSLP) can also directly augment the expression of OX‐40 ligand on the surface of DCs, thereby promoting Th2 cell functionality and facilitating the progression of allergic asthma [74].