[1] Hannover Med Sch, Dept Gastroenterol & Hepatol, Hannover, Germany
[2] Univ Calif San Diego, Ctr Canc, Dept Chem & Biochem, La Jolla, CA 92093 USA
[3] Univ Calif San Diego, Ctr Canc, Dept Pharmacol, La Jolla, CA 92093 USA
[4] Univ Calif San Diego, Dept Pharmacol, La Jolla, CA 92093 USA