2. Binding Affinities and Structural Information of Selected Primary Small Molecule Hits .

^aThis table summarizes the binding affinities (K_d) and chemical structures of all compounds tested for interaction with the CD28 protein. Binding affinities are reported in micromolar (μM) or millimolar (mM) concentrations, with standard deviations where available. ND indicates that the binding affinity was not determined due to lack of dose–response effect. Non-specific binder denotes compounds that exhibited a dose–response effect but did not show selective binding to the active flow cell.