M2‐type macrophages secrete a variety of immunosuppressive factors, which inhibit the anti‐tumor activities of T cells, NK cells, etc., creating a microenvironment conducive to tumor growth.[61] IFN‐γ can reverse the polarization state of macrophages, transforming them from the M2 type to the M1 type and enhancing the local anti‐tumor immune response.[62] The cytokines secreted by γδ T cells are mainly IFN‐γ. This evidence concerns the gene IFNG and neoplasm.