IFNG and nasopharyngeal carcinoma: To substantiate the impact of FLI1 on the IDO1-Kyn pathway, we employed western blot and qPCR analyses, revealing that only in the presence of IFN-γ, FLI1 KO resulted in a decline in both mRNA and protein levels of IDO1 in NPC cells (Fig. 2D, E and Supplementary Fig. S2B).