Recently, two novel astrocytic PET tracers have been developed:[11C]-BU99008, which targets imidazoline binding site (I2B) overexpression in AD brains,19,20 and [18F]-SMBT-1, which is similar to [11C]-deuterium-l-deprenyl with high selectivity for MAO-B. Here, MAOB is linked to Alzheimer disease.