To directly address the specific role of macrophage-derived netrin-1 in AAA, mice harboring Ntn1 gene flanked by lox-P sequences were bred with mice expressing the Cre recombinase in mature macrophage lineage within the lysozyme C-2 gene Lyz2 (LysMcre) to generate Ntn1flox/floxLysMcre+/− (Ntn1−/−Mø) and Ntn1flox/floxLysMcre-/- Nnt1l−/− (WTMø) control mice. Here, NTN1 is linked to triple-A syndrome.