1. Stephan Angelov Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
2. University of Claude Bernard Lyon 1, France.
3. Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
4. Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
5. Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas.