In SMM, the presence of serum monoclonal protein (IgG or IgA) ≥3 g/dL or urinary monoclonal protein ≥500 mg per 24 h and or clonal bone marrow plasma cells 10–60%, and the absence of myeloma-defining events or amyloidosis is established as the diagnostic criteria (23). The gene discussed is CD79A; the disease is amyloidosis.