The activation of an immunosuppressive environment promoting tumor growth also includes the inhibition of differentiation and maturation of dendritic cells (DCs), NK cell cytotoxicity, inactivation of proapoptotic pathways, inhibition of antigen presentation, disorders in receptor signaling of T cells, and activation of negative co-stimulatory signals like CTLA-4 (cytotoxic T-lymphocyte-associated protein 4)/CD80 (or CD86) and PD-1 (programmed death 1)/PDL-1 (programmed death ligand 1) [33]. Here, CTLA4 is linked to neoplasm.