CD68 and atherosclerosis: Using the same Ldlr−/− chimeric model, we did not observe any impact on atherosclerosis using mice with FcγRIIb overexpression driven by the macrophage-specific CD68 promoter29 (Figure IIE through IIH in the online-only Data Supplement), suggesting a more influential role for FcγRIIb-mediated control of B cells on atherosclerosis.