Anti-FcεR1a mAb immunostaining and immunofluorescent co-staining together with an anti-Ki67 rabbit polyclonal antibody of AAA lesion sections from Apoe−/−Fcer1a−/− recipient mice receiving donor CD8+ T cells from Apoe−/− mice showed the presence of donor CD8+ T cells in AAA lesions (Supplementary Fig S8B and S9A, left two panels) and these donor cells also underwent clonal expansion (Supplementary Fig S9B). Here, FCER1A is linked to triple-A syndrome.