Biomarkers in body fluids offer additional insight into multiple sclerosis (MS) pathogenesis, disease characteristics of different MS phenotypes, and monitoring treatment responses. Over the last decades we have witnessed an evolution from smaller single center studies on primarily cerebrospinal fluid (CSF) biomarkers to larger multicenter collaborations also involving blood-based biomarkers, with clear implications for changing clinical practices and improving treatment outcomes. Excellence in future MS biomarker research, but also rarer neuroinflammatory disorders, requires efforts to collaborate even more closely in the future. To this end leading European research groups in MS and related disorders have formed the BioMS-network to serve as a platform for collaboration and optimization of soluble biomarker research.