Novel adherent CD11b Gr-1 tumor-infiltrating cells initiate an immunosuppressive tumor microenvironment.

The immunosuppressive tumor microenvironment is a hallmark of cancer. Myeloid-derived suppressor cells (MDSCs) are CD11b Gr-1 tumor-infiltrating immature myeloid cells that strongly mediate tumor immunosuppression. The CD11b Gr-1 cells are a heterogeneous cell population, and the impacts of each subpopulation on tumor progression are not yet completely understood.