TGFB1 and inflammatory bowel disease: In addition to generating products that can activate regulatory immunity by triggering the host TGFβ pathway, helminths have also been shown to decrease expression of the TGFβ inhibitor Smad7 by host cells, and using a T-cell transfer model of colitis, the critical role of Smad7 downregulation in helminthic regulation of IBD was shown [82].