IDO1 and neoplasm: Interestingly, tumor draining lymph nodes (TDLNs) have an increased amount of CD19+ plasmacytoid DCs (CD19+pDCs) expressing IDO that gives them a function phenotype of tDCs, creating a local immunosuppressive TIME by suppressing the host antitumor immunity, including the T cell immunity and directly activating the mature Tregs [87].