A combinatory treatment with CF33-hNIS-ΔF14.5 and anti-PD-L1 antibody resulted in an absolute tumor regression in a triple-negative breast cancer mouse model. Whereas treatment with either CF33-hNIS-ΔF14.5 or anti-PD-L1 antibody did exert any significant therapeutic effect. The gene discussed is CD274; the disease is neoplasm.