However, when mRNA levels of VCAM-1, ICAM-1 and E-selectin were studied in isolated retinal vessels from ApoE−/− using the same assays as for intact retina, a clear increase of ICAM-1 in response to diabetes was observed (p<0.05) and similar trends were seen for VCAM-1 and E-selectin (n.s.; Figure 3B). Here, APOE is linked to diabetes mellitus.