Generation and phenotype of cultured MDSCs. (A) Fluorescence-activated cell sorter phenotype of B6 whole BM at day 4 of culture that has been left untreated, treated with G-CSF alone (100 ng/mL), treated with GM-CSF alone (250 U/mL), or treated with both G-CSF and GM-CSF. All gates based on isotype controls. Ly6G/Ly6C graphs were first gated on CD11b⁺ cells. Representative images of hematoxylin and eosin-stained cytospins of MDSCs with combined treatment (B) and combined treatment plus IL-13 addition on day 3 (C) Photographs were taken using 400× magnification with a RT-Spot camera mounted on an Olympus BX51 microscope (Olympus).