ALB and neoplasm: First, the magnitude of tumor uptake exceeds blood pool, which itself is somewhat high, and the tumor uptake is above the range of what might be considered EPR.12 In preclinical models, 89Zr-albumin has been used to quantify signal due to EPR in subcutaneous xenografts, and the highest uptake observed was ∼5% ID/g.12 Second, the contrast enhancement observed on this patient’s staging CT was uniform across the 14 hepatic lesions, yet only 4 lesions were PET avid.