Multiple myeloma (MM) is a clonal plasma cell malignancy, characterized by the proliferation of neoplastic plasma cells. Delineation of the mechanisms mediating plasma cell proliferation, survival and migration in the bone marrow microenvironment may enhance the understanding of pathogenesis, and a better understanding of the molecular pathogenesis is fundamental to developing more effective prognostic, therapeutic and preventive approaches. It is still an incurable disease but the introduction of novel therapies and stem cell transplantation have altered the natural course of the disease, transforming it into a chronic disease from a terminal illness.