1. Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA
2. Department of Dermatology, College of Physicians & Surgeons, Columbia University, New York, NY 10032, USA
3. Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA
4. Present address: Samuel Oschin Comprehensive Cancer Institute, Los Angeles, CA 90048, USA
5. Division of Dermatopathology, Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294-4550, USA
6. Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA