Professional Activities

• Director, Clinical Trace Metals Diagnostic Lab, Department of Pediatrics, University of Oklahoma, Oklahoma City, OK, USA, 08/1979 – 07/1982
• Assistant to Associate Professor, Department of Pediatrics (Tenured 1983), University of Oklahoma, Oklahoma City, OK, USA, 07/1979 – 06/1989
• Scientific Director, Biochemical Genetics Lab, Oklahoma Children's Hospital, Okla City, OK, USA. 07/1980 -06/1987
• Consultant, Medical Service, Veteran's Administration Medical Center, Oklahoma City, OK, USA.  07/1981 -06/1987
• Scientific Director, Trace Metals Diagnostic Lab, State of Oklahoma Teaching Hospi­tals, Oklahoma City, OK, USA, 07/1982 – 06/1988
• Associate Member, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA, 07/1987 – 06/1989;
• Professor, Department of Pediatrics (Tenured 1990), Georgetown University, Washington, DC, USA, 07/1989 – 06/2009
• Director, Molecular Genetic Diagnostic Lab, Georgetown University Children's Medical Center, Washington, DC, USA, 07/1993 – 06/2000
• Chief, Division of Genetics and Metabolic Diseases, Department of Pediatrics, Georgetown University, Washington, DC, USA, 07/1998 – 06/2000
• Senior Scientist, Head and Principal Investigator, Section on Developmental Genomics, Laboratory of Clinical Genomics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA, 07/2006 – 06/2009
• Professor of Biomedical Sciences and Founding Director, School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, (United College) 06/2009 – 07/2018
• Director, CUHK - BGI Innovation Institute of Trans-Omics, the Chinese University of Hong Kong, Hong Kong, 08/2011 – 07/2017
• Director, CUHK - Chinese Academy of Science Kunming Institute of Zoology Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Hong Kong, 06/2012 – present
• Director, CUHK - Chinese Academy of Science Guangzhou Institute of Biomedicine and Health (CAS GIBH) Joint Research Laboratory on Stem Cell and Regeneration, Hong Kong, 08/2012 - present
• Director, CUHK – Shandong University Joint Laboratory on Reproductive Genetics, Hong Kong, 06/2013 – present

Visitng And Guest Professorship

• Adjunct Assistant to Associate Professor, Department of Biochemistry & Molecular Biology, University of Oklahoma, Oklahoma City, OK., 1979-1989.
• Visiting Scientist, Department of Biochemistry, University of Washington, Seattle, WA, July 1-Dec 31, 1982.
• Visiting Professor, Cancer Institute, Chinese Academy of Medical Sciences, and Institute of Basic Clinical Sciences, China-Japan Friendship Hospital, Beijing, China, May 12-15, 1987.
• Affiliate Member, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA, 1989-2009.
• Professor, Department of Biochemist­ry and Molecular & Cellular Biology (Secondary), Georgetown University, Washington, DC, USA, 1989-2009.
• Member, Vincent T. Lombardi Cancer Center, Georgetown University, Washington, DC, USA, 1989-2009.
• Visiting Professor, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, March 18-20, 1991
• Visiting Scholar, Shaw College, Chinese University of Hong Kong, Hong Kong, Jun 29-Jul 5, 1993
• Adjunct Investigator, Laboratory of Clinical Genomics, NICHD, NIH, Bethesda, MD, USA,, 2001-2006
• Visiting Professor, Department of Pediatrics, Queen Elizabeth Hospital, Hong Kong, 2007
• Professor (courtesy), Department of Biochemistry (2009-2010), School of Life Sciences (2010- present), Faculty of Science, the Chinese University of Hong Kong, Hong Kong, 2009-2013
• Professor (courtesy), Department of Pediatrics, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, 2009-2018
• Adjunct Scientist, Laboratory of Developmental and Clinical Genomics, Intramural Research Program, NICHD, NIH, Bethesda, MD, USA, 2010-2013
• Guest Professor, Faculty of Medicine, Zhejiang University, Zhejiang, China, 2010-present
• Honorary Professor, Faculty of Life Science and Technology, Jinan University, Guangzhou, China, 2010-present
• Professor (courtesy), Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, 2011-2016
• Special Professor, Faculty of Medicine, Shenzhen University, China, 2011-2014
• Adjunct Professor, Department of Biochemistry and Molecular & Cellular Biology, Georgetown University School of Medicine, Washington, DC, USA, 2011-present
• Visiting Scientist, 2010-2014, Distinguished Professor, Jan 2014-Dec 2020, Chinese Academy of Sciences, Guangzhou Institutes of Biomedicine and Health, Guangzhou, Guangdong, China
• Guest Professor, Shandong University, Shandong, China, 2012-2015
• Professor (joint appointment), Chongqing Medical University, Sichuan, China, 2014-2016.