While C3, C3aR, C5aR, and C5L2 blockade/deficiency can protect from liver failure and improve sepsis survival in mice [51, 52], by contrast, the presence of these same proteins, as well as the C3 products ASP and C3a, plays roles in promoting liver regeneration, liver transplant tolerance, and protection from steatosis [9, 37, 53, 54]. This evidence concerns the gene C5AR2 and liver failure.