The quantitative analysis of liver collagen, the major extracellular matrix protein in liver fibrosis [4], with the Sirius red collagen-binding assay [19] (Figure 1C), demonstrated that C/EBPβ-Ala217 mice were refractory to the development of liver fibrosis after chronic exposure to the hepatotoxin. This evidence concerns the gene PROS1 and Hepatic fibrosis.