MAPK1 and amyotrophic lateral sclerosis: ERK signaling dysfunction is related to a variety of neurological abnormalities such as Huntington’s disease (HD), Parkinson’s disease (PD) [16], Alzheimer’s disease (AD) [23], amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, ischemia [24], asthma [25] and cancer [26].