<h4>Background</h4>The inflammatory cytokine thymic stromal lymphopoietin (TSLP) has pleiotropic roles in immune response and tissue homeostasis, yet its function in abdominal aortic aneurysm (AAA) remains entirely unexplored.<h4>Methods</h4>We integrated clinical epidemiology, <i>in vivo</i> experimental models, and <i>in vitro</i> mechanistic assays. Here, TSLP is linked to triple-A syndrome.