KDM1A and amyotrophic lateral sclerosis: As guanidines have been shown to inhibit both spermine oxidase (SMO/PAOh1) and other polyamine oxidases, we sought whether arginine supplementation and polyamines (spermidine and spermine) administration will effectively inhibit the endogenous expression or activity of LSD1 and whether the subsequent modulation of LSD1 could lead to the protection of motor neurons and improve neuropathology of ALS.