Unbiased hierarchal clustering (Supplementary Figure S3) was also performed to reveal trends of gene expression in different gene target groups which demonstrated substantial portions of the MCI group and a small part of the dementia group clustered together with high expression levels of the top aging genes associated with IL-7Rα low EM CD8+ T cells (represented by the “Top IL-7Rαlow aging genes” category in Supplementary Figure S3, the cluster indicated by a blue arrow), though there was more variability and heterogeneity in clustering of the rest of the participants. The gene discussed is CD8A; the disease is dementia.