1. Stem Cell Project Group (R.-S.F., K.Tan., T.H.), The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Bunkyo-ku, Tokyo 113-8613;
2. Laboratory of Animal Experiment for Disease Model (M.M.), Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815;
3. Department of Endocrine Pharmacology (R.F., K.Tam., H.K.), Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan