NOS2 and oral cavity squamous cell carcinoma: For example, low‐dose irradiation programs macrophage differentiation into an iNOS+/M1 phenotype that orchestrates effective T‐cell immunotherapy.[28] In oral squamous cell carcinoma, local irradiation causes vascular damage and hypoxia in the tumor and increases the infiltration of CD11b+ myeloid cells, which are characteristic of M2 macrophages and associated with the promotion of vascularization.[29] Our research revealed that after RT, there is strong crosstalk between tumor cells and macrophages, leading to macrophage polarization.