MMP9 and abdominal aortic aneurysm: In addition, a recent study noted that knockdown of PVT1 decreased levels of MMP-2 and MMP-9, augmented TIMP-1 expression, and suppressed serum levels of TNF-α, IL-1β, and IL-6 in VAMC and ApoE-/- mice of abdominal aortic aneurysm model [32].