GDF2 and Hepatic fibrosis: Our recent work has demonstrated that BMP9 is upregulated in experimental models of liver fibrosis and more importantly, loss of BMP9 signalling (BMP9-KO and ALK1-Fc mice) results in a significant decrease in the CCl4-induced fibrotic process, as evidenced by lower Col1a1 expression and decreased collagen fibres in the tissue and lower αSMA protein levels in the liver [69].