In addition to the alteration of CD8+ T cells in the PB and CSF, the presence of CD8+ T cells is also observed in the brains of both AD patients (Itagaki et al., 1988; Merlini et al., 2018; Unger et al., 2020) and AD model mice (Laurent et al., 2017; Unger et al., 2020; Michael et al., 2021; Fernando et al., 2023). The gene discussed is CD8A; the disease is Alzheimer disease.