Therefore, MS lesion development is a three-step process; first, activated T cells in the perivascular space express IFN-γ, then the surrounding IFN-γ exposed glial cells express CXCL9 and CXCL10, leading to CXCR3-expressing T cells infiltrating the inflammation site. This evidence concerns the gene CXCL9 and myeloid sarcoma.