NOS2 and neoplasm: Tumour cells present autoantigens to DCs and activate T cell differentiation, thus affecting tumour development through Treg cells, CD4+ T cells and CD8+ T cells by immune actions.66 Nitric oxide synthase (NOS2)‐ and tumour necrosis factor (TNF)‐producing DCs are important for adoptively transferred CD8(+) cytotoxic T cells to destroy tumours.67 In addition, immunosuppressive cells such as Treg cells can secrete immunosuppressive molecules that are known to induce DC dysfunction.68