Monoclonal gammopathy of undetermined significance (MGUS) is defined by the presence of a serum monoclonal protein (M-protein) at a level < 3 g/dl, clonal bone marrow plasma cells <10%, and the absence of end-organ damage (lytic bone lesion, anemia, hypercalcemia or renal failure) related to the proliferative process [7,8]. The gene discussed is MYOM2; the disease is anemia (phenotype).