During the course of CNS diseases like multiple sclerosis or Alzheimer’s disease, and in the corresponding animal models, the chemokines CXCL9 and CXCL10 are abundantly expressed at sites of glial activation, arguing for an important role of these chemokines and their corresponding receptor CXCR3 in glial activation. This evidence concerns the gene CXCL9 and multiple sclerosis.