Increased activity of WNT5a/β-catenin is contributed to the indoleamine 2,3-dioxygenase 1 (IDO1) induction in tumor-associated DCs [30], which is seemingly mediated through peroxisome proliferator-activated receptor-γ (PPARγ) activation [52] and further reprogramming of DC metabolism from glycolysis into oxidative phosphorylation [14] (Fig. 3). Here, IDO1 is linked to neoplasm.