CD8A and Alzheimer disease: Flow cytometry confirmed the scRNAseq data, showing a dramatic increase in the percentage of GrK-producing CD103–CD8+ Trm cells (both GrKMED and GrKHIGH) infiltrating the brain, but not the meninges, of 3xTg-AD mice compared to WT controls, whereas no differences were observed for brain-infiltrating CD103–GrK– CD8+ T cells (Fig. 3k–m; Supp.