[1] Univ Cologne, Cologne, Germany
[2] Univ Hosp Gasthuisberg, B-3000 Louvain, Belgium
[3] Univ Calif Los Angeles, Los Angeles, CA USA
[4] Duke Univ, Med Ctr, Durham, NC USA
[5] Johannes Gutenberg Univ Mainz, D-6500 Mainz, Germany
[6] NCI, Bethesda, MD 20892 USA
[7] Weill Cornell Med Coll, New York, NY USA
[8] Silesian Med Univ, Katowice, Poland
[9] Sahlgrens Univ Hosp, Gothenburg, Sweden
[10] Singapore Gen Hosp, Singapore 0316, Singapore
[11] Univ Pisa, Pisa, Italy
[12] Schering Plough Corp, Res Inst, Kenilworth, NJ 07033 USA