Nevertheless, D isomer (D-1MT) is equally effective in inhibiting the enzymatic activity of IDO in human monocyte-derived DCs in allogeneic mixed lymphocyte reactions (MLRs) and is significantly superior to L-1MT or DL mixture in inducing T-cell proliferation in allo-MLRs using either human T cells stimulated by IDO-expressing monocyte-derived DCs or murine T cells stimulated by IDO-expressing plasmacytoid DCs from tumor-draining lymph nodes [69]. Here, IDO1 is linked to neoplasm.