Finally, BAFF Index did not correlate to CSF CXCL13 concentrations in HC (r −0.36, p = 0.2), MS patients (r −0.29, p = 0.1), IgGOB− (r −0.05, p = 0.9), and IgGOB+ (r −0.31, p = 0.1). The gene discussed is TNFSF13B; the disease is myeloid sarcoma.