The expansion of the CD4+HLA-G+ population was markedly predominant in patients with AD compared with HCs, SC and CD (median 23.54%; IQR (13.28–29.69) vs 4.61%; (2.18–8.81) 7.09%; (1.83–12.25) and 5.14 (2.62–6.97)), respectively (Kruskal-Wallis p<0.0001) (figure 1A). Here, CD4 is linked to Alzheimer disease.