kapp values at various concentrations of sCAR (monomer calculated using Kd from the work of Patzke et al. [46]) in DMEM (open circles) and DMEM with FBS (9.3% to 10%; solid circles). Data obtained with DMEM-10 and published in reference 17 are shown for comparison (gray circles). The kapp values with and without FBS at 95 nM sCAR monomer (100 nM total sCAR) are significantly different. Differences with and without FBS at 224, 413, and 728 nM sCAR monomer (250, 500, and 1,000 nM total sCAR) are not statistically significant at a P of 0.05.