Wells were coated with different ligands at concentrations which produce maximal cell adhesion (as described in Figure 3). Calcein-labeled α_Dβ₂-expressing HEK 293 cells were incubated with 200 μg/mL P2-C or with a mixture of P2-C and anti-β_t antibody diluted 1:500 for 20 minutes at 22°C and then added to the coated wells. Adhesion was quantitated as described in “Materials and methods.” Results are expressed as a percentage of inhibition of adhesion, with adhesion in the absence of competing agents defined as 0% inhibition. The data shown are means ± SE of 3 individual experiments, each with triplicate measurements.