Fig. 2: Smoldering multiple myeloma cohort included in the study.

Those SMM patients with a serum M-protein of ≥3 g/dL or urinary M-protein ≥ 500 mg per 24 h were classified as “myeloma-like” with the remaining patients classified as “MGUS-like.” MM multiple myeloma, SMM smoldering multiple myeloma, MGUS monoclonal gammopathy of undetermined significance, Int intermediate, LR low risk, IR intermediate risk, HR high risk. An asterisk (*) represents patients’ missing data for SMM and MGUS risk stratification.