The roles of TSLP and IL33 in allergy were evaluated in TSLP receptor (TSLPR)- and IL33 receptor-deficient (T1/ST2) mice, respectively; TSLPR- and T1/ST2-knockout mice showed strong Th1 responses with high levels of IL2 and IFN-γ and impaired the Th2 response (59–61). This evidence concerns the gene IL2 and allergic disease.