VEGFA and neoplasm: Recently, MDSCs have also been implicated in tumor refractoriness to anti-VEGF treatment.(22) Bv8 (prokineticin 2), expressed in the bone marrow, modulates mobilization of CD11b+Gr-1+ cells from the bone marrow during tumor development and also promotes angiogenesis locally.(23) These studies suggest that tumor-infiltrating bone marrow–derived MDSCs change the dynamics in the primary tumor microenvironment and result in alterations in the signaling cascade in tumor cells, promoting tumor cell invasion and metastasis.