Our previous studies have shown the immunotherapeutic potential of heteroclitic XBP1 US184-192 (YISPWILAV) and XBP1 SP367-375 (YLFPQLISV) peptides to generate XBP1 antigen-specific CTL, and we demonstrate here that lenalidomide can enhance anti-tumor activities of XBP1-CTL against a variety of solid tumors which overexpress XBP1 antigen. The gene discussed is XBP1; the disease is neoplasm.