TNF and nasopharyngeal carcinoma: In the present study, we used an OGD-treated NPC-cultured model in vitro which demonstrated that: (1) the expression of IDO in NPCs increased under the OGD condition, which was closely related to cell survival; (2) the inhibition of IDO could attenuate NPC viability; and (3) increased IDO is closely associated to growth factors TNFα, FGFβ, and Leptin expression.