A drug that is similar to thalidomide, and is used with rituximab to treat follicular lymphoma and marginal zone lymphoma in adults who have already received other treatment. It is also used alone or with dexamethasone to treat multiple myeloma in adults. Lenalidomide is also used in adults to treat anemia caused by certain types of myelodysplastic syndromes and to treat mantle cell lymphoma that came back or got worse after treatment that included bortezomib. It is also being studied in the treatment of other conditions and types of cancer. Lenalidomide may help the immune system kill abnormal blood cells or cancer cells. It may also prevent the growth of new blood vessels that tumors need to grow. Lenalidomide is a type of antiangiogenesis agent and a type of immunomodulating agent. Also called CC-5013 and Revlimid.