IDO1 and neoplasm: Comparing 0 and 10 day with day 14 post TC-1 transplantation, we observed a concomitant decrease in the number of IDO1-expressing DCs (Figure 2A), macrophages (Figure 2B), inflammatory monocytes (Figure 2C) and MDSCs (Figure 2D) in spleen and blood of TC1-grafted mice, which suggests that these cells are migrating to the tumor site.