A deficit of Ca2+ uptake results in reduced mitochondrial motility and neuronal loss in Huntington's disease mice (Panov et al, 2002), and Sig1R−/− or NE‐100‐treated neurons showed elongated mitochondria with lower motility in axons to cause axonal degeneration and progressive death of primary neurons (Bernard‐Marissal et al, 2015). Here, SIGMAR1 is linked to juvenile Huntington disease.