Professor Leung is an endowed professor in Department of Paediatrics at The Chinese University of Hong Kong. Professor Leung is a Co-Chair of Microbiome and Biodiversity Committee of Asia Pacific Association of Allergy, Asthma and Clinical Immunology and Past President of Hong Kong Society for Paediatric Immunology, Allergy and Infectious Diseases. He has published more than 450 articles in peer-reviewed journals with H-index of 50. His main research interests include natural history, novel diagnostics, genetics and host-microbe interactions of allergic diseases.