These studies established that loss of SIL1 led to activation of the UPR coinciding with the onset of muscle weakness, which drove the upregulation of numerous ER chaperones, co-chaperones, and ERAD components, suggesting that the basal levels of these protein folding machineries were sufficient to maintain ER homeostasis before the onset of myopathy [86,87]. The gene discussed is SIL1; the disease is myopathy.