TSPO and amyloidosis: PET using various 18 kDa translocator protein (TSPO) tracers have demonstrated an early microgliosis preceding the Aβ deposition in several animal models of amyloidosis including APP23, hAPP-J20, APPSL70, AppNL-G-F, and PS2APP mice [76,77,215,222,223,224,225].