Department of Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA. Electronic address: daniel.nixon@vcuhealth.org. Center for Biostatistics and Research, Harvard School of Public Health, Boston, MA, USA. Division of Medical Laboratory Science, School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, USA. West Virginia Clinical and Translational Science Institute, West Virginia University, Morgantown, WV, USA. Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA, USA. Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA. HIV Research Branch, DAIDS, NIAID, NIH, Bethesda, MD, USA. Infectious Diseases Clinical and Translational Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA.