In particular, CXCL13 has recently been suggested as a prognostic marker for CIS and MS (Brettschneider et al., 2010; Ferraro et al., 2015; Magliozzi et al., 2020) and seems to play a role in the formation of ectopic lymphoid tissues within the CNS in MS (Magliozzi et al., 2007). This evidence concerns the gene CXCL13 and in situ carcinoma.