Oil-Red-O staining (Fig. 6A) and H&E histologic staining (Fig. 6B–E) revealed an aggressive lesion development on vessel wall of HCD-ApoE−/− mice (Fig. 6A3, D), while no obvious lesion was observed in either wild-type C57/BL6 control mice fed with HCD (HCD mice) (Fig. 6A1, B) or ApoE−/− mice fed with normal diet (ND-ApoE−/− mice) (Fig. 6A2, C). This evidence concerns the gene APOE and heavy chain disease.