GDF2 and Hepatic fibrosis: Lately, BMP9 was shown to induce the proliferation and elevate the expression of α-smooth muscle actin (α-SMA) and collagen proteins in hepatic stellate cells, and thereby promote hepatic fibrosis (Li, Zhao et al., 2008; Bi and Ge, 2014; Breitkopf-Heinlein et al., 2017; Li et al., 2018).