Resveratrol suppresses tumor progression via the regulation of indoleamine 2,3-dioxygenase

► Resveratrol inhibits the expression and activity of IFN-γ-induced IDO. ► Resveratrol suppresses IDO via JAK/STAT and PKCδ. ► IDO suppression by resveratrol is crucial for T cell polarization and CTL response. ► Rresveratrol suppresses EG7 thymoma growth in an IDO-dependent manner.