[1] UCL, Inst Hepatol, London, England
[2] Mortimer Market Ctr, London, England
[3] Manchester Royal Infirm, Manchester M13 9WL, Lancs, England
[4] Hannover Med Sch, D-3000 Hannover, Germany
[5] Univ Bologna, Bologna, Italy
[6] Univ Turin, Turin, Italy
[7] INSERM, F-69008 Lyon, France
[8] Gilead Sci Inc, Foster City, CA 94404 USA