S-NFL levels, just like recently reported for CSF-NFL levels [13] in this cohort, did not differ between CIS patients and RRMS patients (p = 0.9 for S-NFL and p = 0.4 for CSF-NFL) or between patients with and without a relapse starting within 2 months prior to sample collection at baseline (p = 0.7 for S-NFL and p = 0.1 for CSF-NFL). The gene discussed is NEFL; the disease is in situ carcinoma.