In contrast, we observed that the level of the full-length of IL-33 but not the short-form of IL-33 was substantially increased in the thymus of mice with schistosomiasis (Fig. 3a), which may be due to a low level of cleaved IL-33 or lack of cleaving proteases of IL-33 in the thymus during schistosome infection28. This evidence concerns the gene IL33 and schistosomiasis.