Abstract: For the past few years, growing evidences have shown that bone marrow-derived myeloid cells play a key role in regulating the formation of blood vessels in tumors. Myeloid cells promote tumor angiogenesis in various manners, including VEGF secretion and VEGF independent way. The latter constitutes the mechanism of tumor refractoriness to anti-VEGF therapy. Myeloid cells also promote tumor recurrence after radiotherapy or chemotherapy. Last, we discuss its concomitant therapeutic implications.

Key words: tumor angiogenesis, myeloid cells, clinical treatment