18F-FDG, CT, and 64Cu-TP3939 PET of TRAMP mouse. TRAMP I mouse harbored grade II early intraepithelial neoplasia. The benign lesion was not visible on 18F-FDG, CT, and 64Cu-TP3939 PET. TRAMP II mouse harbored grade IV well-differentiated prostate adenocarcinoma. The malignant prostate lesion was detected on 64Cu-TP3939 but missed on 18F-FDG and CT. The solid arrow indicates high bladder uptake of 18F-FDG. In contrast, bladder uptake is absent with 64Cu-TP3939. As the primary route of excretion is fecal, there are some background activity of 64Cu-TP3939 in the colon (oval-head arrow) (This research was originally published in Zhang et al. [25]. Copyrighted by the Society of Nuclear Medicine and Molecular Imaging, Inc.)