APOE and diabetes mellitus: To investigate the effects of diabetes on VCAM-1 expression, as well as the potential role of TNFα, C57BL/6 wild-type (wt), ApoE−/−, TNFα−/− and ApoE−/−/TNFα−/− mice were chow-fed until 22 weeks of age, injected with STZ or vehicle once a day for 5 days and kept on chow diet for additional 8 weeks.