To explore the possible mechanism causing delayed tumor growth, histochemical analysis of the a2v‐mAb‐treated tumor tissues displayed high immune cell infiltration (M1‐macrophages, neutrophils, CD103+ cells, and NK cells) and an enhanced antitumor response (iNOS, IFN‐y, IL‐1α) compared to control. The gene discussed is NOS2; the disease is neoplasm.