APP and early-onset autosomal dominant Alzheimer disease: In this study we compared the recently developed TSPO tracer [18F]F-DPA, with [18F]DPA-714 and [11C]PBR28 by performing in vivo PET imaging on the same Alzheimer’s disease mouse model APP/PS1-21 (TG) and wild-type (WT) mice with all three radiotracers.