CXCL13 and primary central nervous system lymphoma: In the literature, CSF CXCL13 elevation was also demonstrated for other diseases such as chronic infections (HIV, neurosyphilis) and autoimmune diseases (including multiple sclerosis or anti-NMDAR encephalitis) [20, 23, 25, 39–43], which are more prevalent in the adult population and were not represented in our study; as well as CNS lymphomas and some bacterial infections [19, 20, 44], which show a very different clinical picture and were not included in our study.