Wang Y, et al. - As proteases, including cysteinyl cathepsins, mediates the extensive extracellular matrix remodeling that leads to aortic wall weakening in an abdominal aortic aneurysm (AAA), researchers investigated if patients with AAA differed from healthy controls in terms of plasma cystatin B levels. They analyzed plasma samples from patients with AAA and age matched controls from the Viborg Vascular (VIVA) screening trial for AAA. This study does not support the prior studies suggesting a negative association between cystatin C and AAA development. Findings here showed a positive correlation between cystatin B and AAA size and associations between cystatin B tertile at baseline and AAA presence and need for later surgical repair. It seems that these two cystatins possibly inhibit cathepsin activity and contribute to AAA with different mechanisms.