MDSCs contribute to cancer progression through several mechanisms. They inhibit the activity of T cells and natural killer (NK) cells, which are crucial for anti-tumor immunity. Additionally, MDSCs promote the expansion of regulatory T cells (Tregs), which further suppress the immune response. These cells also secrete various enzymes and cytokines, such as arginase, nitric oxide synthase, and reactive oxygen species, which create an immunosuppressive microenvironment that favors tumor growth and metastasis.
