HLA-A and breast cancer: To determine whether CMVp495–503-encompassing peptides were loaded onto HLA-A*02:01 at the cell surface without cellular internalization or after cellular uptake and processing, each synthetic peptide and TEDbody, either at 4 °C for 3 h or at 37 °C for 18 h, was extracellularly applied to human breast cancer MDA-MB-231 cells expressing both integrin αvβ5 and HLA-A*02:01 (Fig. S2).