Multiple sclerosis/CIS patients with clinical or radiographic relapse symptoms, gadolinium-enhancing T1 lesions, or enlarging T2 lesions in MRI had elevated CSF-CXCL13 levels compared to those in patients with primary or secondary progressive MS (PPMS/SPMS) [44,45,46,47]. This evidence concerns the gene CXCL13 and secondary progressive multiple sclerosis.