In patients receiving donor lymphocyte infusion (DLI), CD8+ T-cell depletion decreases the incidence of GvHD.9–11 In atherosclerosis, we and others have previously demonstrated a pro-atherosclerotic role of CD8+ T cells in early lesion formation in Ldlr−/− and apolipoprotein E-deficient mice.21,22 Given that the enhanced atherosclerotic lesion formation in BMT-transplanted mice was associated with increased proportions of activated allogeneic CD8+ T cells displaying heightened cytotoxicity in the aorta, we assessed the role of CD8+ T cells in atherosclerotic lesion formation in our model. Here, LDLR is linked to atherosclerosis.