1. Center for Advanced Stem Cell and Regenerative Research, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan
2. Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan
3. Department of Oral and Maxillofacial Surgery, Fukuoka Dental College, Fukuoka 814-0193, Japan
4. Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
5. Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan
6. Department of Urology and Molecular Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan