CD86 and aortic aneurysm: The IF analysis revealed upregulated levels of H3K18la and increased CD86 expression in the AAA group, and H3K18la co-localized with CD86 in the aortic aneurysm, suggesting both an expansion of M1 macrophages and enhanced H3K18la levels within these M1 macrophages during AAA pathogenesis (Fig. 1H).