INPP5D and neoplasm: SHIP restricts the M2 polarization of Mφs in 4T1 tumor-bearing mice, which is particularly important since M2-Mφs are key promoters of tumorigenesis in this model and there have been a number of recent reports that restricting alternative activation of Mφs can decrease 4T1 tumor growth and metastasis [28, 47–49].