FOXP3 and neoplasm: It is well-established that the tumor microenvironment is highly immunosuppressive and modulated by the tumor cells themselves as well as the recruitment of immunosuppressive CD4+CD25+FoxP3+ regulatory T cells (Tregs), CD11b+Gr-1+ myeloid-derived suppressor cells (MDSC), and M2-polarized macrophages (23–25).