CXCL13 and in situ carcinoma: OCB were shown to be an independent risk factor implementing an almost two-fold increased risk of having a second relapse [9], and we demonstrated the polyspecific intrathecal B cell response against neurotropic viruses MRZR as well as the B-cell attracting chemokine CXCL13 to be of prognostic relevance in CIS [23], [24].