Indeed, multiple studies have reported an increased number of CD8 + T cells in AD brain parenchyma relative to control brain tissue (Togo et al., 2002; Merlini et al., 2018; Chen et al., 2023) and in tauopathy mouse models (Laurent et al., 2017; Lee et al., 2021; Chen et al., 2023). This evidence concerns the gene CD8A and Alzheimer disease.