In this study, one-half of the subjects will be chosen at random to receive the study drug and the other half will take a placebo pill (a sugar pill that looks the same as the real medication). This is a double blind study where neither the subjects nor the investigators know whether the patient receives the study drugs or placebo pills. The effects of the active drug lenalidomide will be compared to the effects of the placebo. The results from this study will be also be compared with a similar but separate study to be done on individuals without known disease.