CD4 and Alzheimer disease: CD4+ T cells are the dominant cellular infiltration in AD and are differentiated into Th1, Th2, Th17, Th22, and regulatory T cell subsets (Bieber et al., 2022), increased frequencies of Th1, Th2, Th17, and Th22 cells together with an excessive accumulation of their inflammatory cytokines play vital roles in AD pathogenesis (Grewe et al., 1998; Weidinger and Novak, 2016).