The widely accepted model of liver regeneration. (A) Liver regeneration. A normal mouse liver after 70 or 30% PHx (Day 0), and regenerated liver after 70 (Day 7) or 30% PHx (Day 4) are shown. Scale bars; 1 cm. (B) Liver weight change during liver regeneration after 70% PHx. The regeneration requires circa 14 days to recover the original liver weight. The error bars are S.D. (n = 3–7 for each day). (C) The currently accepted model of liver regeneration. In 70% PHx, the median lobe (ML) and the left lobe (LL) are removed, and the right lobe (RL) and caudate lobe (CL) regrow to restore the liver mass. In the traditional model, each hepatocyte is thought to divide once or twice during liver regeneration after 70% PHx. Potential alterations in size, nuclear number, and ploidy of hepatocytes are not taken into consideration.