Here, we aimed to validate these results in individual CSF samples using alternative techniques.<h4>Methods</h4>In a first replication study, levels of apolipoproteins AI and AIV, vitronectin, and plasminogen were measured by ELISA in CSF and serum of 56 CIS patients (29 patients who converted to CDMS (MS converters) and 27 patients who remained with CIS during follow-up (MS non-converters)) and 26 controls with other neurological disorders. Here, VTN is linked to in situ carcinoma.