NOS2 and triple-A syndrome: With CaCl2 incubation, AAA was induced in 73% of mice in a C57 background (Figure 8A, 8B), the maximum abdominal aorta diameter was increased and the protein levels of NICD, hes1 and M1 macrophage marker iNOS were upregulated (Figure 8A, 8B, 8D, 8E, 8F).