Immunofluorescent co-staining of AAA lesions from Apoe−/−Fcer1a−/− recipient mice receiving donor CD4+ T cells from Apoe−/− mice for FcεR1a and Ki67 demonstrated that donor CD4+ T cells not only targeted to the AAA lesions, but also underwent clonal expansion (Fig 3B). Here, APOE is linked to triple-A syndrome.