EGF and liver disorder: Similarly, a recent study reported that IL-6, co-operated with epidermal growth factor (EGF) and HGF, could promote the long-term expansion (> 30 passages in ~ 150 days with theoretical expansion of ~ 1035 times) of primary mouse hepatocytes in vitro (Fig. 2) [31], which may effectively resolve the limited application of hepatocyte transplantation in liver diseases due to a shortage of enough hepatocytes.