CD8A and Alzheimer disease: Notably, scRNAseq analysis revealed an almost three-fold reduction in the abundance of CD103+CD8+ Trm cells in the brains of 3xTg-AD mice (WT = 27.44%, 3xTg-AD = 9.8%) with a parallel increase in the abundance of CD103–CD8+ Trm cells (WT = 45.9%, 3xTg-AD = 73.69%) (Fig. 2c).