HDAC6 and amyotrophic lateral sclerosis: Inhibition or genetic deletion of histone deacetylase 6 (HDAC6), an enzyme that, among other functions, removes acetyl groups from microtubules, improved axonal transport and neurodegeneration in models of neurodegenerative diseases such as ALS, Huntington’s and Parkinson’s [185,186,187,188,189].