In 2006, the first proteomic analysis of CSF samples from ALS patients demonstrated that a VGF fragment of 4.8 kDa (ARQNALLFAEEED or ARQN-13 at proVGF398–410 sequence) was able to discriminate (through its decrease) with high sensitivity and specificity between patients with ALS (n = 49) and patients with other neurologic disorders (n = 5; multifocal motor peripheral neuropathy; n = 2; sensorimotor peripheral neuropathy) or normal subjects (n = 46) analyzed using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-MS) proteomics technique [73]. Here, VGF is linked to amyotrophic lateral sclerosis.