Fig. 1

Diagram of the generation of Th17 cells and the association with other factors. While TCR is activated, TGF-β and IL-6 activate transcription factors Smads and STAT3 and induce the expression of ROR, so that naive T cells differentiate to Th17, which secretes IL-21 and in turn promotes the process in a positive feedback manner continually. IL-17 inhibits the production of CXCL9/10 from tumor cells, thus stop CD8⁺ CTLs and Tregs from infiltrating tumor cells