CD8A and Alzheimer disease: Previous studies have shown that the immune system is closely related to AD (Mietelska-Porowska and Wojda, 2017), and our study showed that CD8 T cells, B cells, dendritic cells, mast cells, MDSCs, natural killer cells, and natural killer T cells were more highly infiltrated in AD patients, consistent with previous research (Salminen et al., 2018; Dai and Shen, 2021; Harcha et al., 2021).