CYCS and amyotrophic lateral sclerosis: One of the earliest abnormalities common to multiple neurodegenerative diseases, including frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), is mitochondrial dysfunction, which is often detected by reduced mitochondrial respiration, calcium mishandling, lower membrane potential (Δψm), cristae structure disorganization, fission/fusion imbalance, and cytochrome c release (leading to apoptosis) [1,2,3].