ACTA1 and Hepatic fibrosis: PAR1(−/−) BMT mice accumulated significantly less liver fibrosis than equivalent WT BMT controls (2.65+/−0.10% vs. 3.11+/−0.08%, collagen surface area, p = 0.004) after CCl4 injury, and had significantly lower density of activated myofibroblasts (1.40+/−0.10% vs. 1.99+/−0.21%, αSMA+ histological percentage surface area, p = 0.01, figure 5).