However, various parameters related to the neuro-axonal damage induced by the inflammatory activity of MS are correlated with increased NfL levels in the CSF and in the blood: presence of a relapse (Barro et al., 2018), presence and number of gadolinium-enhancing lesions on gadolinium injection on MRI (Gd+), indicating “active” lesions (Novakova et al., 2017; Varhaug et al., 2018), increase in the number of new lesions on MRI (Bittner et al., 2020), and the brain volume (Barro et al., 2018). This evidence concerns the gene NEFL and myeloid sarcoma.