The combined treatment of MMH NPs with OX40 (20.0 μg per mouse), an anti-OX40 antibody that decreases the immunosuppressive TME, demonstrated an excellent antitumor effect and tumor inhibition due to higher DC activation (5.0% ± 1.7%) and reduced immunosuppressive response (reduction to 2.0% ± 0.9% MDSCs and 0.4% ± 0.3% M2 macrophages), which resulted in greater CD4+ (4.5% ± 0.5%) and CD8+ (2.5% ± 0.5%) T cells infiltration in the tumor. Here, CD4 is linked to neoplasm.