TILs do not respond to N-class I-peptides. TILs were stimulated with 5- or 10 μM N-class I-peptides for 5 days. 5 replicate wells were tested for proliferation, and proliferation was measured by 3H-thymidine incorporation assay. The proliferation strength is depicted as SI. (#) indicates the peptide that was used in the 1st to 4th vaccinations. Data are expressed as mean ± SEM.