PLAU and severe combined immunodeficiency: Several groups have reported the generation of chimeric mice with transplantation of human hepatocytes into immunodeficient mice [e.g., urokinase-type plasminogen activator/severe combined immunodeficiency (uPA/SCID) mice (Tateno et al., 2004), Fah−/−/Rag2−/−/Il2rg−/− mice (Azuma et al., 2007), and TK-NOG mice (Yamasaki et al., 2010)].