AGT and abdominal aortic aneurysm: Abdominal aortic aneurysm is pathologically described by the dilatation of abdominal aorta resulted from destructive extracellular matrix (ECM) and inflammatory response.3, 4 Angiotensin II (Ang II) is the key effective hormone in the rennin‐angiotensin system, which prompts matrix degradation, vascular remodelling as well as chronic inflammation in the abdominal aorta.