Equilibrium binding of plasminogen is observed to viable human peripheral blood monocytes and viable Hoxa9-ER4 cells. Human peripheral blood monocytes (A) were either untreated (○) or treated with M-CSF (●) as in Figure 1 and Hoxa9-ER4 cells (B) were treated with M-CSF as in Figure 1 and subjected to quantitative flow cytometry with increasing concentrations of FITC-plasminogen as described in under “Quantitative flow cytometry.”