VAPB and amyotrophic lateral sclerosis: VAPB, an ER transmembrane protein involved in the regulation of vesicle trafficking, showed a strong correlation with the neuronal marker ENO2 as well as MNX1, a marker for mature motor neurons.35, 36 In addition, we demonstrated that VAPB localized to large motor neurons in human spinal cord34 dividing ALS cases from healthy control even better than the well‐established motor neuron marker ChAT.