VDR and Hepatic fibrosis: With regard to the relationship between VDR polymorphisms and clinical outcomes, an in vitro analysis showed that VDR ligands inhibited transforming growth factor (TGF)-β1-induced hepatic stellate cell activation and reduced liver fibrosis, while, in a mouse model, genetic knockout of VDR expression led to spontaneous liver fibrosis (Ding et al., 2013).