[1] Tumor Biol Ctr, Freiburg, Germany
[2] Univ Hosp Freiburg, Freiburg, Germany
[3] Bayer HealthCare Pharmaceut, West Haven, CT USA
[4] Bayer Schering Pharma AG, Berlin, Germany
[5] Bayer HealthCare, Wuppertal, Germany
[6] Univ Essen Gesamthsch, Sch Med, Essen, Germany
[7] Univ Hosp Bochum, Marienhosp Herne, Herne, Germany