Blockade of the interaction of VCAM-1 with its ligand, the very late antigen-4 (VLA-4), has been tested in animal models and also in clinical trials in relapsing remitting MS patients showing a significant reduction of relapse rates and MRI activity which led to the development of a new drug for MS treatment (natalizumab) [5-7]. This evidence concerns the gene VCAM1 and myeloid sarcoma.