Definition of non-responders: biological markers.

Identification of reliable biomarkers in multiple sclerosis patients would be highly desirable to help disease activity and progression monitoring, and evaluate response to treatments. The field has gradually shifted from the aim to find the perfect surrogate marker to the construction of composite markers with higher performances, taking advantage of the technologies allowing unbiased screening (i.e., microarrays, proteomics, etc.). Despite the fact that very interesting results have been produced, no approach has yet made it to the patient's bedside.