ITGAM and neoplasm: Although many in the field of MDSC biology use a ≥48-h T cell suppression assay to show that M-MDSCs from BM, spleen, and tumor are all functional (11, 17, 38–41), we previously showed that unfractionated tumor CD11b+Gr-1+ MDSCs could suppress T cell proliferation immediately upon isolation in a short-term assay but that spleen MDSCs could not (12, 13).