It has been shown that CSF-NfL levels have the ability to predict the development of new lesions in MRI, clinical relapses, progression of disability, and response to treatment in MS patients (Lycke et al., 1998[64]; Teunissen et al., 2009[101]; Håkansson et al., 2017[44]). The gene discussed is NEFL; the disease is myeloid sarcoma.