For example, Tregs from H. polygyrus or T. spiralis‐infected mice transferred protection against airway pathology in models of experimental airway allergy.43, 46, 118Heligmosomoides polygyrus excretory/secretory products (HES) can induce Tregs in vitro, and transfer of HES‐induced Tregs can replicate the suppressive capacity of the parasitic infection.119 Recently, a TGF‐β mimic (Hp‐TGM) was identified in HES, a protein which alone can induce Tregs in vitro.120, 121. This evidence concerns the gene TGFB1 and parasitic infectious disease.