VEGFA and myeloproliferative disorder: The available data on angiogenesis and expression of VEGF and its receptors in the bone marrow of patients with BCR-ABL1-negative myeloproliferative neoplasms (MPN) suggest that MVD is increased, especially in primary myelofibrosis (PMF), and that increased angiogenesis might inversely correlate with survival [55-58].