IDO1 and neoplasm: As there is evidence that IDO1 may restrict tumor growth as a mediator of tumoricidal IFN-γ in experimental models and patients [16], [17], [18], [19], [20], [21], [22] and as IDO1 expression in tumors positively correlated with progression-free survival and long-term survival in some studies [23], [24] it is tempting to speculate that the induction of IDO1 by 1-D-MT may actually account for some of the anti-tumor effects of 1-D-MT.