PTGDR2 and Alzheimer disease: T-cell subsets of special interest, such as CRTAM+ CD8A+ T6 and PTGDR2+ IL17RB+ “Th2A” cells, previously associated with the AD skin disease memory35, as well as proliferating T cells, were absent in healthy control individuals, but present in all AD groups and in DAHND (Fig. 3D, E).