Because the majority of our autopsied patients were included in a previous report that demonstrated group-level differences between CBS-AD and CBS-FTLD [7], we tested the predictive value of CBS variants in an independent cohort of patients who underwent positron emission tomography (PET) imaging with the beta-amyloid ligand Pittsburgh compound B (PIB-PET) as a surrogate marker of AD pathology [15]. Here, CBS is linked to Alzheimer disease.