Because of cyclophosphamide’s ineffectiveness in sustained Treg cell depletion during MVA-5T4 vaccination, we would propose the combination of MVA-5T4 with more potent blockade of tumor-derived immunosuppression for future development, for example with anti–CTLA-4 to eliminate intratumoral Treg cells or with anti–LAG-3 checkpoint inhibitors, given the extent of infiltration of highly suppressive LAG-3+CD4+ tumor-infiltrating T cells. The gene discussed is CTLA4; the disease is neoplasm.