CXCL13 and small cell lung carcinoma: One patient with paraneoplastic syndrome (sensomotoric polyneuropathy) due to small cell lung cancer with the detection of Zic4-antibodies had a CXCL13 value of 836 pg/mL, and lastly, a patient with the first diagnosis of Neuro-Behçet’s disease with di-mesencephalic-pontine lesions with contrast-enhancement in the T1 MRI-sequences had a CSF-CXCL13 level above the determined cut-off (CSF-CXCL13: 1150 pg/mL).