Blockade of IDO-kynurenine-AhR metabolic circuitry abrogates IFN-γ-induced immunologic dormancy of tumor-repopulating cells.

Tumour repopulating cells (TRC) are stem-like cells that can escape immune-mediated killing. Here, the authors show IFN-γ results in either dormancy or apoptosis of TRC depending on the activation of the IDO1 metabolic pathway, and that combining IFN-γ with IDO1 inhibitors results in enhanced tumour regression.