Relative expression of cytokines after siRNA-mediated IDO knockdown. (A) and (B) Relative mRNA expression levels of IFN-γ and TNF-α were quantified by qRT-PCR. The mRNA levels of IFN-γ and TNF-α were significantly higher in the siRNA620 group than in the control and control siRNA groups (***p < 0.001). (C) qRT-PCR analysis of IL-10 mRNA expression. The IL-10 mRNA level was significantly lower in the siRNA620 group than in the control and control siRNA groups (***p < 0.001).