[11C]UCB-J is a PET tracer for imaging the synaptic vesicle protein 2 A (SV2A) that is ubiquitously expressed in the synapses in human brains and has garnered interest as an important biomarker of synaptic loss in various disorders including schizophrenia, Alzheimer’s disease, and substance use disorders [1]. The gene discussed is SV2A; the disease is Alzheimer disease.