The data demonstrated that combination treatment with anti-CTLA-4 mAb and MUC1 mRNA nanovaccine could reduce immunosuppressive TME, increase the infiltration of CD8+ T cells into tumor sites, and enhance anti-tumor cytotoxic T-lymphocyte activity when compared to monotherapy with either anti-CTLA-4 mAb or MUC1 mRNA nanovaccine. Here, CTLA4 is linked to neoplasm.