CD4 and Alzheimer disease: Finally, in vivo studies showed that the topical administration of S. epidermidis EVs in an AD-like dermatitis model attenuated lesion formation and reduced AD-like inflammatory features, such as epidermal thickness, dryness, transepidermal water loss, pruritus, epidermal cell infiltration (CD4+ T cells and Gr1+ cells), Th2 cytokine gene expression (IL-4, IL-13 and TLSP), and IgE levels [36].