GADD45A and Hepatic fibrosis: Another notable aspect of this study is that EZH2 and JMJD3 epigenetically modulate HSCs phenotypes through regulating CDKN1A and GADD45. As a potent cyclin-dependent kinase inhibitor, CDKN1A, also known as p21, regulates cell progression, inhibits proliferation and induces senescence of HSCs, which facilitates the resolution of liver fibrosis 56, 57.