Interestingly, immunohistochemical staining of GPR81 found that the upregulated expression of GPR81 was mainly distributed in the typical regions of collagen deposition in liver fibrosis (Goodman 2007; Kleiner et al. 2005; Gailhouste et al. 2010; Hadi et al. 2020). Here, HCAR1 is linked to Hepatic fibrosis.