IDO1 and neoplasm: Blockade of the IDO/AhR metabolic circuitry not only abrogates dormancy induced by IFNγ, but also leads to increased tumor regression.48 These findings uncover a previously unrecognized mechanism underlying IFNγ‐induced TRC dormancy, implying a potential effective combination of IFNγ inhibitors with IDO/AhR inhibitors.