No comparable expansion was observed for CD4<sup>+</sup> ex-Trm cells.<h4>Discussion</h4>Circulating CD8<sup>+</sup> ex-Trm cells with skin-homing properties may contribute to AD progression by reseeding distant skin sites and sustaining inflammation, whereas CD4<sup>+</sup> ex-Trm cells may remain preferentially retained within inflamed skin. Here, CD4 is linked to Alzheimer disease.