Mittra et al (1) describe a new positron emission tomographic (PET) radiopharmaceutical, fluorine 18 ((18)F) 2-fl uoropropionyl labeled PEGylated dimeric RGD peptide (FPPRGD2), a marker of α(v)β(3) integrin expression, which they tested in fi ve healthy volunteers. No adverse events were encountered, and the biodistribution suggested both a renal and a hepatobiliary excretory route. This early safety testing paves the way for future studies of patients with cancer who are undergoing antiangiogenic therapies. (18)F-FPPRGD2 represents one of several integrin imaging agents that are moving closer to clinical reality.