IDO1 and neoplasm: These may include therapies that directly supply T cell chemotactic chemokines, such as CXCL-9, -10, and -11, into tumor or promote their production from tumor cells [70,71,72], or deplete Tregs [73], or therapies that block IFNγ or its induced immunoregulatory effects through blockade of IDO or PD-1.