In conclusion, we report on the critical role of lenalidomide to enhance anti-tumor activities (IFN-γ production, granzyme B upregulation, memory CTL proliferation) of XBP1 antigen-specific CTL through upregulation of key T cell activation markers/costimulatory molecules and downregulation of inhibitory molecules, which were associated with induction of Th1-specific transcription regulators and a signal integrator. Here, XBP1 is linked to neoplasm.