1. Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
2. Basic Science Program, Leidos Biomedical Research, Inc., NCI Center for Cancer Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
3. HIV Drug Resistance Program, NCI, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
4. Nanotechnology Characterization Lab, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
5. Gene Regulation and Chromosome Biology Laboratory, Center for Cancer Research, NCI, National Cancer Institute, Frederick, Maryland 21702, United States