NEFL and myeloid sarcoma: Natalizumab‐treated patients show a 3‐fold decrease in NFL, indicating that this treatment not only has an immunomodulatory effect but may also reduce axonal damage.10 These effects are also observed in patients with MS who were treated with rituximab, mitoxantrone, or fingolimod.11, 12 However, studies have not demonstrated conclusively that the decline in axonal involvement is not secondary, and anti‐NF antibody levels do not correlate with the clinical variants of MS.13, 14