Stratification of AD patients according to IFNG expression levels and IFN-γ-secreting T cell capacity reveals two distinct subgroups: IFN-γ-high AD (exhibiting predominant endogenous AD characteristics) and IFN-γ-low AD (manifesting classical exogenous AD features) (28), which is consistent with previous studies (29, 30). This evidence concerns the gene IFNG and Alzheimer disease.