ACTA1 and Hepatic fibrosis: In recent years, the S1P axis is also emerging as an important player in hepatic fibrogenesis; S1P is known to have an important influence on several hallmarks of liver fibrosis development (Li et al., 2009a, 2011), since this biomolecule upregulates the expressions of ECM proteins such as TGF-β, alpha-smooth muscle actin (α-SMA) and collagen I and III.