1 Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina.
2 Department of Dermatology, Duke University Medical Center, Durham, North Carolina.
3 Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina.
4 Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina; Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina. Electronic address: david.kirsch@duke.edu.