CD4 and type 1 diabetes mellitus: Additionally, human islets EVs are able to specifically activate memory T cells derived from T1D patients but not those from non-diabetic control subjects, as documented by a significant increase of CD69 MFI in both memory T-cells (CD4+CD45RO+CD45RA−CCR7−CD62L−) and B-cells (CD19+IgD−CD27+) observed in T1D PBMCs (134).