The CSF NfL levels were significantly reduced after immunosuppressive treatment with mitoxantrone.38 Cerebrospinal fluid NfL levels were also tested in MS patients treated with natalizumab, with marked decrease during treatment.31 Cerebrospinal fluid NfL levels were also studied in patients treated with fingolimod, and reduced levels were observed after the treatment.39 Patients treated with fingolimod with no reduction in CSF NfL levels had clinical and MRI deterioration. This evidence concerns the gene NEFL and myeloid sarcoma.