TGFB1 and idiopathic pulmonary fibrosis: In vivo, however, the role for αVβ6 and αVβ8 in TGF-β activation is still under investigation, although expression of αVβ3 and αVβ5 is up-regulated in systemic sclerosis and αVβ5 is detected in the fibroblast foci of patients with IPF (Asano et al., 2005).