1. Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan.
2. Department of Periodontics, Stomatology Hospital of Xi'an Jiaotong University College of Medicine, Xi'an, People's Republic of China.
3. Sanford-Burnham Medical Research Institute, Cancer Center, Tumor Microenvironment and Metastasis, La Jolla, California.