Wada et al. have demonstrated the importance of timing with the combination of anti-CTLA-4 mAbs and GM-CSF gene-transfected tumor cell (GVAX) vaccine in the prostate cancer model Pro-TRAMP (67), by showing that anti-CTLA-4 mAbs should be administered after vaccination to produce additive effects. The gene discussed is CTLA4; the disease is prostate carcinoma.