In patients with optic neuritis (ON), the levels of NF-H phosphorylated form (NF-HSM135) in plasma [71], or its hyperphosphorylated form in CSF (NF-HSM134) [69], as well as CSF NF-HSM135 levels in CIS patients [25], were found to be significantly higher compared to controls (Table 1). Here, NEFH is linked to in situ carcinoma.