So many individuals and organizations have assisted in the research that made this book possible that it would be impossible to mention them all. I am particularly indebted to the staff and volunteers of AIDS Concern (Hong Kong), The Warehouse, and Operation Dawn, as well as various doctors and patients at Queen Elizabeth Hospital. Some of the work reported here was made possible by grants from the Health Care and Promotion Fund (Grant # 257102), the AIDS Trust Fund (Grant # PPE227), and the Hong Kong Research Grants Council General Research Fund (Grant # CityU 144110). Special thanks also go to my mentors and colleagues, especially Ron and Suzanne Scollon, and Chris and Sally Candlin, who have provided guidance and inspiration over the years. Finally, I would like to thank Danyal Freeman for his valuable comments and editorial support and Lynn Zhang and Li Chi Hang for assistance in preparing the bibliography and index. As usual, while I am indebted to these individuals and organizations for their help and support, any inaccuracies or omissions in this manuscript are my responsibility alone.