BDNF and amyotrophic lateral sclerosis: Here, we will just name GFs that are known to contribute to ALS and were successfully tested in vivo for the purpose of neuroprotection or disease modification, those are: glia cell-line derived neurotrophic factor (GDNF), insulin growth factor type-1 (IGF-1), brain-derived neurotrophic factor (BDNF), neural growth factor (NGF), VEGF and others that play less significant role in ALS pathology.