B2M and anemia: Regarding clinical characteristics (as illustrated in Figure S2), a log-rank test showed that high β2M (Figure S2A), low albumin (Figure S2B), ISS stage > 2 (Figure S2C), and to a lesser extent anemia (Figure S2D), high creatinine levels (Figure S2E), and older age (Figure S2F) predicted shorter OS of patients (p = 0.0004, p = 0.003, p = 0.01, p = 0.06, p = 0.08, p = 0.09, respectively).