[1] Baylor Coll Med, Houston, TX 77030 USA
[2] MD Anderson Canc Ctr, Houston, TX USA
[3] Canc Therapy & Res Ctr S Texas, San Antonio, TX 78229 USA
[4] Georgetown Univ, Washington, DC USA
[5] Ligand Pharmaceut, San Diego, CA USA
[6] Natl Canc Inst, Bethesda, MD USA