The standardized uptake value ratio (SUVR) retention patterns of [11C]PBB3 differed significantly from that of [11C]PIB, suggesting that [11C]PBB3 binds tau selectively over Aβ.38 Accumulation of [11C]PBB3 was seen in the medial and lateral temporal cortices, and the frontal cortex—consistent with the Braak staging theory of AD.38, 39 When tested in a corticobasal syndrome patient [11C]PBB3 retention was high in the neocortex and subcortical structures. The gene discussed is MAPT; the disease is Alzheimer disease.