XBP1 and Hepatic fibrosis: First, both sXBP1 and uXBP1 signatures were strikingly induced in a mouse HSC-specific database of two commonly used experimental models of mouse liver fibrosis, carbon tetrachloride (CCl4) and bile duct ligation (BDL), implicating XBP1 activation in HSCs irrespective of the etiology (Fig. 5).