WT1 and melanoma: To probe the mechanistic basis of these observations, we used surface plasmon resonance to measure the binding affinities of the CD8αα variants S53G and S53N for HLA-A2 refolded around three different clinically relevant peptide epitopes, namely preferentially expressed antigen of melanoma (PRAME)425–433 SLLQHLIGL (SLL), PRAME100–108 VLDGLDVLL (VLD), and Wilms’ tumor protein 1 (WT1)126–134 RMFPNAPYL (RMF).