2021-Present Professor, College of Veterinary Medicine, Seoul National University
2017-2021 Associate Professor, College of Veterinary Medicine, Seoul National University
2011-2017 Associate Professor, Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee
2008-2011 Associate Professor (Tenured), University of Tennessee, College of Veterinary Medicine, Department of Pathobiology, Knoxville, TN
2003 -2008 Assistant Professor, University of Tennessee, College of Veterinary Medicine, Department of Pathobiology, Knoxville, TN
2002-2003 Research Fellow, NIEHS, NIH
1998-2002 IRTA Fellowship, NIEHS, NIH