In P-MS patients, one logarithmic unit (~2.7 ng/ml) increase in CCL18 was associated with decrease in GMV (44.4 ml), in CV (32.4 ml), in DGMV (5.8 ml), and in thalamic volume (2.1 ml) and with increase in T2-LV (25 ml). The gene discussed is CCL18; the disease is myeloid sarcoma.