CMV has been associated with downregulation of cell-mediated immunity, resulting in increased cellular and inflammatory markers commonly linked to cognitive decline.CMV-specific CD8+ T cells can generate interferon γ, and there is a significant correlation between increased levels of CMV IgG antibodies and higher levels of TNF-α and IL-6 in older adults. This immune and inflammatory pathway linked to CMV is related to cognitive decline and AD. Here, CD8A is linked to Alzheimer disease.