1. Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Gilead Sciences and IOCB Research Centre, Flemingovo nám. 2, CZ-166 10, Prague 6, Czech Republic
2. Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
3. Gilead Sciences, Inc., 333 Lakeside Drive, Foster City, California 94404