1 Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 2108, Bethesda, MD, 20892, USA.
2 Molecular Histopathology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
3 Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 2108, Bethesda, MD, 20892, USA. mgottesman@nih.gov.