While TLOs formation was noticed in the brains of SPMS patients but not in primary-progressive MS (PPMS) or RRMS by Serafini et al. [19], intracerebral expression of CXCL13 and BAFF was shown to be accompanied by formation of lymphoid like structures in animal model of relapsing EAE [21]. Here, CXCL13 is linked to primary progressive multiple sclerosis.