Defining progression of abdominal aortic aneurysm (AAA) is complicated by several factors, including measurement error, duration of follow-up, and the imaging modality used to assess AAA expansion. Investigations of biomarkers of AAA progression should be standardized so that valid comparisons can be made. Previous research has shown some promising advances towards identifying a reliable and individual predictor of AAA progression. In this second part of our Review on biomarkers of AAA progression, we examine direct and indirect markers of inflammation including various cytokines, C-reactive protein, activators of tissue plasminogen activator and urokinase plasminogen activator, and osteopontin.