PAR1 mediates the cytoprotective effect of plasminogen. Human peripheral blood monocytes were exposed to 10 ng/mL TNFα in the presence (open symbols) or absence (closed symbols) of 2 μM plasminogen and either the presence of anti-PAR1 (ATAP2) (squares) or isotype control (diamonds) (each at 20 μg/mL) for 24 hours. The cells were analyzed by flow cytometry using annexin V–FITC and PI, and data were normalized to 100% for antibody in the absence of plasminogen. Symbols represent anti-PAR1 antibody without plasminogen (▪), isotype control without plasminogen (♦), anti-PAR1 antibody plus plasminogen (○), isotype control plus plasminogen (⋄). The closed diamonds are superimposed on the closed squares. Data are shown as mean ± SE, n = 2, for a representative of 3 independent experiments.