IDO1 and colorectal carcinoma: Ifit1high Stat1low CRC (tumor cell-intrinsic Stat1-Ido1↑, stromal Stat1↓, similar to Stat1flox/floxApcMin tumors) displayed a higher percentage of late-stage IV tumors than Ifit1low Stat1high CRC (tumor cell-intrinsic Stat1-Ido1↓, stromal Stat1↑, similar to Stat1∆IECApcMin tumors) (Fig. 5g, h), suggesting that tumor cell-intrinsic Stat1-Ido1 promotes CRC progression.