In a study of 19 glioma patients treated with bevacizumab (humanized antibody against VEGF) and irinotecan (an inhibitor of topoisomerase I), Chen et al. (19) showed that responders, defined as those with a 25% or greater decrease in SUV, survived 3 times as long as non-responders (10.8 vs. 3.4 months); they concluded that FLT–PET was a better predictor of overall survival compared with MRI. The gene discussed is VEGFA; the disease is central nervous system cancer.