In addition, the TME often inhibits T-cell proliferation, promotes T-cell apoptosis, down-regulates expression of MHC molecules and antigen processing machinery components on most cells within tumors (in particular neoplastic cells, DCs, and CD4+ T helper cells) and corrupts TAMs toward an M2 immunosuppressive phenotype, thereby allowing tumor cells to escape attack from the immune system. The gene discussed is CD4; the disease is neoplasm.