This issue of PET Clinics focuses on Radiotracers, and is edited by Drs. Neil Vasdev and Abass Alavi. Articles will include: PET/CT detection of HER2-positive metastases in patients with 89Zr-DFO-trastuzumab; uPAR-PET with 68Ga-NOTA-AE105: first clinical experience with a novel PET ligand; 64Cu-FBP8: A fibrin-targeted probe for imaging of thrombus; Imaging of synaptic density in the brain via synaptic vesicle glycoprotein 2A (SV2A) with a novel biomarker 11C]UCB-J; Neuroimaging of stress sensitive and neuroinflammatory targets in mood disorders; Impact of MR-based PET motion correction on the quantification of PET kinetic parameters in simultaneous cardiac PET-MR; Multimodal studies of the contributions of amyloid and tau burden to neurodegeneration in AD, FTD and Non-AD tauopathies; Imaging of prostate-specific membrane antigen (PSMA) using 18F]DCFPyL; Ga-68 GRPR antagonist imaging; and more