Moreover, in 30 cases and 30 controls randomly selected from the same cohort, elevation of serum neurofilament light (sNfL) protein, a marker of axonal damage and the first objective sign of MS-induced injury, was observed at a median 6 (range 4–10) years before clinical MS onset.13 Similarly, in our previous report on sNfL in successive 5-year periods,14 average sNfL levels showed an increasing trend starting in specimens obtained 5–10 years before clinical MS onset. This evidence concerns the gene NEFL and myeloid sarcoma.