COL4A1 and Hepatic fibrosis: Liver fibrosis is a disease characterized by collagen deposition [14] and we included in the multiplex assay multiple genes coding for proteins involved in extra cellular matrix formation, deposition and turnover (COL1A1, COL3A1, COL4A1, ACTA2 and TIMP1); and one gene encoding a component of the cytoskeleton (KRT18).