Intrathecal production of CXCL13 was found decreased in patients with non-inflammatory neurological conditions, high in patients with Lyme neuroborreliosis (>250 pg./mL) and moderate high in patients with MS who had focal dysfunction of the blood-CSF barrier (5–100 pg.//mL) (Pachner et al., 2024). Here, CXCL13 is linked to myeloid sarcoma.