Overexpression of tau protects MTs against the severing action of katanin and spastin (Qiang et al., 2006; Yu et al., 2008), while loss of tau in neurodegenerative diseases, such as Alzheimer’s, indirectly leads to increased spastin activity (Zempel and Mandelkow, 2015). This evidence concerns the gene MAPT and neurodegenerative disease.