NEFL and in situ carcinoma: This partly contrasts a previous finding where a correlation of NFL levels with the number of T2 lesions has been described in a combined analysis of patients with CIS or MS.6 Another study found an association of CSF NFH levels with the volume of enhancing lesions in patients with MS.22 However, in our CIS cohort, the prevalence of enhancing lesions was too low to allow such an analysis.