SIRT2 and hereditary spastic paraplegia: This may suggest a role for SIRT2 in the axonal degeneration cascade of neurodegenerative disorders of aging such as MS (McSharry, 2010), ALS (Fischer‐Hayes et al., 2013), X‐linked adrenomyeloneuropathy (X‐AMN) (Fourcade et al., 2015), or the hereditary spastic paraplegias (Fink, 2013).