Adhesion of the α₅β₁-expressing cells to Glu-Pg and Pm. (A) Calcein-labeled mock-transfected HEK 293 cells were preincubated for 20 minutes at 22° C with P2 (200 μM), anti-β₁ mAb 1965 (20 μg/mL), anti-α₅β₁ polyclonal antibody (1:200 dilution), or tranexamic acid (5 mM) and then added to wells coated with Glu-Pg (5 μg/mL), Pm (5 mg/mL), or fibronectin (3 μg/mL). Adhesion was performed as described in the legend to Figure 2. (B) Calcein-labeled K562 cells activated with 10 nM PMA were incubated with mAb 44a (20 μg/mL), tranexamic acid (5 mM), anti-α₅β₁ mAb 1950 (1:200), or a combination of the inhibitors, for 20 minutes, and then added to wells coated with Glu-Pg (3 μg/mL). After 30 minutes of incubation at 37° C, nonadherent cells were removed and adhesion was quantitated.