From 1981 to 2002, Tsui continued his research and teaching in the Hospital for Sick Children and the University of Toronto alternatively. Prior to his appointment as the Vice-Chancellor, he was Geneticist-in-Chief and Head of the Genetics and Genomic Biology Program of the Research Institute at the Hospital for Sick Children and co-founder of The Centre for Applied Genomics. He was also the holder of the H.E. Sellers Chair in Cystic Fibrosis and University Professor at the University of Toronto. He was the President of Human Genome Organisation, the international organization of scientists involved in the Human Genome Project, from 2000 to 2002. He has also served on the editorial boards for 20 international peer-reviewed scientific journals, numerous scientific review panels, and many national and international advisory committees, including the Medical Research Council of Canada, Canadian Genome Research Task Force Committee, Scientific Steering Committee of the National Institute of Biological Science, Scientific Advisory Committee of the China National Center for Biotechnology Development and Human Genome Organization. He is currently member of the Judicial Officers Recommendation Commission, Council for Sustainable Development and Executive Committee, and Executive Committee of the Commission on Strategic Development of the Hong Kong SAR Government. He was appointed Vice-Chancellor of the University of Hong Kong in May 2002 and assumed office as the fourteenth Vice-Chancellor of the university with effect from 1 September 2002. As of October 2011, he had decided not to seek re-appointment. He served until 31 March 2014.
Academic contributions
Tsui became internationally acclaimed in 1989 when he and his team identified the defective gene, namely Cystic fibrosis transmembrane conductance regulator, that causes cystic fibrosis, which is a major breakthrough in human genetics. He has also made significant contributions to the study of the human genome, especially the characterization of chromosome 7, and, identification of additional disease genes.
Tsui became the centre of controversy following Chinese Vice-Premier Li Keqiang's visit to the centenary ceremony of Hong Kong University on 18 August 2011. During the Vice Premier's visit, police used what a review concluded was unnecessary and unjustifiable force to push some students into a stairwell away from the Vice-Premier. Tsui was later accused by the students of pandering to the Chinese central government and failing to protect both student's freedom of speech and expression, as well as academic freedoms. In a statement to the HKU community, Tsui admitted that the security arrangements could have been better planned and organised. He also apologised to the university's students and alumni for not having been able to prevent the unhappy incident. He assured them that "the University campus belongs to students and teachers and it will always remain a place for freedom of expression."
