It is distinguished from smoldering myeloma and monoclonal gammopathy of undetermined significance by a high (>3 g/dL) level of M-protein (monoclonal light chains) and the presence of CRAB (Hypercalcemia, Renal failure, Anemia, Bone pain) symptoms, which include hypercalcemia, renal failure, anemia, and bone pain, suggesting an end-organ damage. This evidence concerns the gene MYOM2 and anemia.