Vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1), granulocyte-colony stimulating factor (G-CSF) and hepatocyte growth factor/scatter factor (HGF) have all been evaluated preclinically for ALS, and all of these molecules have undergone Phase I trials in humans. This evidence concerns the gene VEGFA and amyotrophic lateral sclerosis.