 Prograf is an immunosuppressant that weakens the immune reactions responsible to protect the organism against infections. It is currently available on the market for patients who have received an organ transplant, to prevent rejection. Because of its effect on the immune system, theoretically, Prograf should exert a significant effect in MS. It has been tried in a small number of MS patients at a lower dose than the one used in organ transplant, however the results of the study did not allow to draw definite conclusions on its safety and efficacy in MS. 