1. Department of Dermatology, New England Medical Center, Boston, MA 02111, USA.
2. Tufts University School of Medicine, Boston, MA 02111, USA.
3. Departments of Radiation Oncology and Biochemistry, New England Medical Center, Boston, MA 02111, USA.
4. Departments of Dermatology and Molecular Biology and Microbiology, New England Medical Center, Boston, MA 02111, USA.