Pro-tumor elements, such as regulatory T cells (Tregs) and MDSCs, create an immunosuppressive environment, inhibiting anti-tumor immunity via cytokines (TGF-β and IL-10) and immune checkpoint molecules (PD-L1, CTLA-4, TIM-3, TIGIT, and NRP1) [80, 81]. This evidence concerns the gene CTLA4 and neoplasm.