GAST and gastric cancer: Our previous report on antral tumors in the Gast−/− mice showed that increased expression of Il-1β, of the Tgfβ -family member activin A (AcA) and follistatin (Fst), the bmp/activin antagonist, preceded transformation in the Gast−/− mice antrum [18], suggesting that there are multiple signal transduction pathways that contribute to the development of gastric cancer.