To investigate whether anti-oxidized low-density lipoprotein (oxLDL) and anti-malondialdehyde-oxidized (MDA-LDL) antibodies may explain the observed increased plaque size in FcγrIII–/–/Apoe–/– mice in intermediate-late-stage atherosclerosis, we measured serum levels of anti-oxLDL and anti-MDA-LDL IgM, IgA, and IgG antibody subtypes. Here, APOE is linked to atherosclerosis.