CD8A and neoplasm: (iii) The bases of the immune protection were the anti-tumor Th1 polarization of the TME (i.e., increased levels of IL-12, IFNγ, interferon-stimulated genes and TNF), the development of systemic tumor-specific T-lymphocytes (splenocytes), infiltration of the tumor masses by CD8+ and activated NK cells, and the inhibition of the mechanisms of tumor tolerance, exemplified by the depletion of tumor-infiltrating myeloid-derived suppressor cells (MDSCs) and the restoration of MHC-I expression in tumor cells.