MDSC levels and cytokine production. In preoperative patients, MDSC levels were significantly positively correlated with (A) IL-6 production, and were significantly negatively correlated with (B) IFN-γ and (C) IL-12 production. MDSC, myeloid-derived suppressor cell; IL, interleukin; IFN-γ, interferon-γ; PBMC, peripheral blood mononuclear cells.