NPY and myeloid sarcoma: A recent pathology study based on biopsies of people with MS with a disease duration of 1.9 years,35 found a significant association between neuropeptide Y receptor Y1 (NPY‐Y1R)‐positive axons within lesions and in the surrounding tissue, where anti‐NPY‐Y1R antibody is considered a label for Wallerian degeneration.36