According to the International Myeloma Working Group (IMWG), SMM is defined by ≥10% clonal plasma cells in the bone marrow and/or a serum M-protein level ≥30 g/L, in the absence of CRAB criteria (hypercalcemia, renal failure related to myeloma, anemia, or bone lesions) or amyloidosis [9]. This evidence concerns the gene MYOM2 and hypercalcemia disease.