CD8A and Alzheimer disease: To understand the role of LFA-1 in more detail, we crossed 3xTg-AD mice with Itgal–/– mice lacking functional LFA-1 integrin and observed a significant decrease in the percentage of CD103–CD8+ Trm cells in the brains of 3xTg-AD/Itgal–/– mice compared to 3xTg-AD animals (Fig. 6b, c).