TSLP and allergic disease: Though both studies used HDM as model allergen, difference in length/duration of allergen exposure is likely to explain the discrepancy in the conclusion: IL-33 is preferentially induced during the early stage of HDM exposure (58), thus plays a critical role in the HDM sensitization and initiation of allergy, while TSLP plays a non-redundant role in HDM-mediated allergic pathogenesis.