TGFB1 and neoplasm: The expression of αVβ6 integrin is nearly restricted to epithelial cells and is upregulated in response to morphogenesis, wounding, inflammation, and tumorigenesis.47 In contrast, αVβ8 integrin is widely expressed by epithelial cells,48 fibroblasts,49 macrophages,50 DCs,51 Tregs,52 and different kinds of tumor cells.53 The lack of αVβ6 and αVβ8 integrin activity reproduces the phenotypes of TGF-β1- and TGF-β3-null mice, indicating the central importance of integrin-dependent activation.54,55