A different study found that the levels of miR-155 and miR-21 are increased in bone marrow and spleen MDSCs of tumor-bearing mice; the authors showed that the overexpression of miR-155 and miR-21 induced the expansion of both monocytic and granulocytic MDSCs by targeting SHIP-1 and PTEN, increased the production of ARG1 and iNOS, and enhanced immunosuppression (68). This evidence concerns the gene NOS2 and neoplasm.