Adoptive intratibial transfer of MDSCs reduced circulating B cells as well as pre B and immature B cells in the BM. (A) Percentages and absolute numbers of total B, immature B, and mature B cells were reduced in peripheral blood of congenic CD45.1+ mice on day 7 after intra-tibial injection of BM-MDSCs and Tumor-MDSCs from CD45.2+ tumor-bearing mice (n = 4 mice/group). (B) Percentages and absolute numbers of Pre B and immature B cells were reduced in the BM of congenic CD45.1+ mice on day 7 after intratibial injection of BM-MDSCs from tumor-bearing mice (n = 4 mice/group). *, P < 0.05; **, P < 0.01; ***, P < 0.001.