Mutations in human ATL1 cause a neurodegenerative disease known as hereditary spastic paraplegia (HSP) (Salinas et al., 2008) and mutations in RHD3 lead to defects in plant growth and short and wavy root hairs (Hu et al., 2009; Zhang and Hu, 2013), suggesting a physiological significance of ER network formation. The gene discussed is ATL1; the disease is hereditary spastic paraplegia.