Silencing spastin changes microtubule stability, curls axons, and impairs anterograde and retrograde axonal transport in human HSP patients (Kasher et al., 2009), zebrafish (Wood et al., 2006), and cultured neurons (Yu et al., 2008; Korulu and Karabay, 2011; Fassier et al., 2013). The gene discussed is SPAST; the disease is hereditary spastic paraplegia.