VEGFA and Huntington disease: Although high levels of VEGF are found significantly increased in HD patients when compared with the controls [40], and there is evidence that VEGF causes BBB disruption [40, 41], other reports indicate that VEGF itself has neurotrophic effects, as it stimulates axonal outgrowth and increases the survival of neurons at different regions of the brain [42], and also rescues hippocampal cells from death induced by serum withdrawal [43].