As a result, from recent progress in cancer research, there is an emerging number of endogenous substances associated with inflammation and cancer to choose between, e.g., NF-κB, IL-6, IFN-γ, TNF-α, enzyme indoleamine-2,3-dioxygenase (IDO), and BRAF gene mutations [8,9,10]. This evidence concerns the gene IDO2 and cancer.