INPP5D and neoplasm: Interestingly, CD11b+Gr1+ cells from naïve WT or SHIP−/− mice did not exhibit significant immunosuppressive effects (Fig. 1I), consistent with our previous findings that CD11b+Gr1+ cells must first be activated (i.e., by pro-inflammatory or tumor-derived factors) before acquiring suppressive abilities that are indicative of CD11b+Gr1+ MDSCs [29].