CSF2 and neoplasm: To determine if CD11b+Gr-1−F4/80−MHC-II− e-MDSCs had the capacity to differentiate into mature neutrophils or monocytes in a tumor-free environment in vitro, tumor-derived CD11b+Gr-1−F4/80−MHC-II− e-MDSCs were cultured in a tumor-free complete culture medium supplemented with GM-CSF.