Liver regeneration summarizes the processes by which liver repairs damage (Michalopoulos and DeFrances 1997). Possible origins of liver damage are virus infections, metabolic diseases, drugs, surgery, and injury. The liver is the main metabolic organ which removes drugs and toxins from the blood and has a remarkable regeneration potential. It can regenerate about two third of its mass. The liver is organized in lobes. The lobes consist of the smallest repetitive functional sub-elements called lobules. Lobules have approximately the shape of a polyhedron. Mouse liver has about 1,000 and human liver about one million lobules. Blood is guided by branches of the hepatic arteries and veins to the periportal regions of the liver lobule. From there it flows through microvessels, called sinusoids, along columns of hepatocytes aligned by endothelial cells until it drains into the central vein, located approximately in the center of each lobule. This architecture guarantees a maximum...