Given the relationship of circulating IL-6 to persistent human DVT and an established role for leukocytes in thromboinflammation, in this study we hypothesized that: IL-6 would be locally elevated in experimental venous thrombosis in both the thrombus and vein wall; that thrombus leukocytes would be a major source of thrombus IL-6; and that IL-6 would play a critical role in thrombus resolution. The gene discussed is IL6; the disease is deep vein thrombosis.