Binding and off-rate curves for selected peptides binding HLA-A*0201. The number associated with each survivin (SRV) peptide corresponds to where the nonamer starts in the survivin amino acid sequence. Curves are fitted using Graphpad's Prism® software. (a) Peptide titration curves. The ED50 for each peptide is taken as the concentration of peptide at which 50% maximal binding of the positive control occurs. (b) Off-rate curves. The half-life (T½) is taken as the amount of time it takes for 50% of the fluorescence measured at time 0 to decay.