IFNG and colon adenocarcinoma: In a murine model of colon adenocarcinoma, dual inhibition of IDO1 and PD-L1 increased the percentage of intra-tumoural CD4+ IFN-γ+ and CD8+ IFN-γ+ T cells, compared with either therapy alone,19 suggesting that the increased levels of IFN-γ might mediate induction of IDO2.