TGFB1 and idiopathic pulmonary fibrosis: Moreover, studies have reported elevated levels of VCAM-1 in IPF lungs, especially in fibrotic areas and blood vessels, and its levels correlate with worse lung function; TGF-β1 increases VCAM-1 in lung fibroblasts, while VCAM-1 depletion reduces their proliferation by affecting ERK1/2 and cyclin D1 [91].