VEGFA and neuroblastoma: In addition, the anti-angiogenic action of melatonin was evident in a co-culture system with human neuroblastoma cells and endothelial cells, where melatonin inhibited Vascular endothelial growth factor (VEGF) expression in the tumor cells and therefore, decreased the levels of the proangiogenic factor available for endothelial cells, reducing proliferation, migration and tube formation in the endothelial cells8.