IL-13 is a 10kD unglycosylated protein, secreted mainly by activated T helper 2 cells. IL-13 binds to IL-4ra in addition to IL-13Ra1 and IL-13Ra2. And the function of IL-13 partially overlaps with IL-4. Both IL-4 and IL-13 link to signal transducer and activator of transcription 6 (STAT6) through the receptor activation. IL-13 can induce B-cell proliferation and IgE classs switching. However, IL-13 is less competent in this function comparing with IL-4. Unlike IL-4, IL-13 does not play an important role in hematopoietic cell shift, such as naive T helper 0 differentiation to T helper 2. IL-I3 signaling is significant in inducing physiological changes to non-immuno cells in parasitized organs. For example, IL-13 induces enhanced gut contractions and glycoprotein hypersecretion which lead to the detachment of helminthes from gut wall. Eggs produced by Schistosoma mansoni can be limited inside granulomas formed through IL-13 induced cell changes. To organisms resided inside cells, IL-13 s