We previously generated humanized chimeric mice by transplanting h-hepatocytes into the livers of the diseased-liver transgenic mouse model with immunodeficient background. These mice with livers mostly replaced by human (h) hepatocytes have been proved to be useful for research on drug metabolism and toxicity and on intrahepatic pathogens such as hepatitis. However, their small body size prohibited collecting sufficient biological samples and made surgical manipulation difficult, which motivated us to produce humanized larger animal(s) bearing h-hepatocytes.