SIRT6 and amyotrophic lateral sclerosis: The same study also found that the expression of NMNAT2 (nicotinamide mononucleotide adenylyl transferase 2, involved in NAD+ synthesis) and SIRT6 was decreased in the spinal cord of ALS patients, suggesting a deficit of this neuroprotective pathway in humans and highlighting the therapeutic potential of increasing NAD+ levels in ALS [249].