Elevated CXCL13 levels in the CSF have been demonstrated for CNS lymphomas (72), and when elevated together with IL-10 in the CSF, CXCL13 has a >99% specificity for primary and secondary lymphomas, leading to similar proposals that it serves as a biomarker for non-Hodgkin lymphoma involving the CNS (73). The gene discussed is CXCL13; the disease is primary central nervous system lymphoma.