CD4 and Alzheimer disease: AD samples contained elevated infiltration levels of resting NK cells, naïve CD4+ T cells, resting CD4+ memory T cells, M2 macrophages, neutrophils, and monocytes, consistent with previous studies (Saresella et al., 2011; Zhao et al., 2022; Khan et al., 2021; Borkowski et al., 2021).