Lenalidomide (CC-5013) is a substance in the class of immunomodulatory agents. The lenalidomide mechanism of action includes anti-neoplastic, pro-erythropoietic, and immunomodulatory properties. Lenalidomide inhibits proliferation of certain hematopoietic tumor cells, enhances T cell- and Natural Killer (NK) cell-mediated immunity and increases the number of NK T cells.