SIRT1 and neoplasm: SIRT1 gene expression plays a key role in that differentiation, since its depletion in MDSCs from both spleen and subcutaneous solid tumors in mice tend towards an anti-tumoral phenotype with a decrease of immunosuppressive activity, a slower tumor growth and a decrease in arginase, TGF-β1 and IL-10 expression as well as more NO, TNF-α and IL-12 expression.