[1] Natl Taiwan Univ, Coll Med, Grad Inst Microbiol, Taipei 10051, Taiwan
[2] Natl Hlth Res Inst, Taipei, Taiwan
[3] Chinese Univ Hong Kong, Prince Wales Hosp, State Key Lab Oncol S China, Dept Anatom & Cellular Pathol, Hong Kong, Hong Kong, Peoples R China