VEGFA and neoplasm: However, VEGF is stored in circulating white blood cells and platelets (Nielsen et al, 1999; Salven et al, 1999b) and several reports have indicated, that elevated VEGF concentrations in serum may be a reflection of degranulation of platelets and white blood cells during in vitro clotting, rather than a reflection of an ongoing angiogenic activity in the tumour (Webb et al, 1998).