Plasminogen decreases caspase activity. U937 cells were preincubated in either the absence (▪) or presence (▨) of 2 μM plasminogen for 30 minutes, and then 10 ng/mL TNFα, 50 μg/mL CHX, or buffer was added and further incubated for 24 hours. Active caspase 3 (A), active caspase 8 (B), and active caspase 9 (C) were determined as described in “Materials and methods.” Data are given as mean ± SE (n = 3). The raw data have been normalized to the untreated cells in the absence of plasminogen (*P < .05).