It is suggested that mutant eIF2B resulted in improper activation of unfolded protein response (UPR) in the condition of endoplasmic reticulum stress, which has been proven in fibroblasts or lymphoblasts from VWM patients, and oligodendrocytes from VWM mouse model [24–27]. The gene discussed is EIF2B5; the disease is leukoencephalopathy with vanishing white matter.