In patients with a baseline diagnosis of non-AD and an inconsistent PET scan, 100% (10/10) changed their diagnosis to AD after a positive amyloid-PET, and 60% (3/5) changed to AD after a positive tau-PET (the two patients with confirmed non-AD diagnosis after positive tau-PET were both diagnosed as FTLD at baseline), a non-significantly different impact (χ2 = 1.8, p = 0.179) possibly due to small sample size. The gene discussed is MAPT; the disease is Alzheimer disease.