[Tumor microenvironment: regulatory cells and immunosuppressive cytokines].

Immunosuppression is a mechanism developed by cancer cells to help them escape the immune system. Immunosuppression involves expansion of various cell types and production of a variety of cytokines. In this review, we explore the duality of three cancer induced cell populations, regulatory T lymphocytes, Th17 lymphocytes and MDSC, and also the pleiotropic effects of several cytokines induced during cancer development.