IDO1 and B-cell chronic lymphocytic leukemia: We analyzed spleen samples from primary Eμ-TCL1 (TCL1) mice with CLL-like disease by flow cytometry and observed elevated expression of IDO1 in MDSC-like classical monocytes and neutrophils in comparison to respective cells in wild-type (WT) mice (Figure 1A,B; Supplementary Figure S1A for gating strategy).