CCL2 and triple-A syndrome: The main pathological process of AAA includes (1) increasing inflammatory response, especially the macrophage infiltration and monocyte chemoattractant protein-1 (MCP-1) expression, (2) activating matrix metalloproteinases (MMP) and depredating extracellular matrix, and (3) degeneration of vascular media and damaging or breaking of elastic fiber [1, 2].