Tumor and ascites DCs originate from peripheral bloodmDCs express IDO and PD-1 and are associated with mmunosuppression of anti-cancer T CD4+ helper and T CD8+ cytotoxic effectorsTumor growth is accompanied by increasing numbers of mDCs, and tumor-derived PGE2 and TGF-β further promote the function of mDCs. This evidence concerns the gene IDO1 and neoplasm.