In our previous studies, XBP1-CTL induced using the HLA-A2-specific XBP1 US184-192 (YISPWILAV) and XBP1 SP367-375 (YLFPQLISV) peptides displayed HLA-A2-restricted and antigen-specific activities against breast cancer, colon cancer and pancreatic cancer cells [18]. Here, XBP1 is linked to breast cancer.