VEGFA and chronic myelogenous leukemia, BCR-ABL1 positive: Furthermore, it has been reported that elevated levels of vascular endothelial growth factor (VEGF), a critical regulator of angiogenesis and neovascularization, are associated with splenomegaly in patients with chronic myeloid leukemia (Liu et al., 2005) and polycythemia vera (Murphy et al., 2002).