Superior overall survival in MGUS-L MM and non–MGUS-L MM lacking amp1q21. (A) Kaplan-Meier estimates of overall survival in MGUS-L MM and non–MGUS-L MM showed superior 5-year actuarial probabilities of event-free survival (64% vs 44%; P = .001) and overall survival (76% vs 59%; P = .009) in patients with MGUS signature. (B) Kaplan-Meier estimates of overall survival in MGUS-L and non–MGUS-L MM according to presence of amp1q21 by interphase FISH. Amp1q21 was not a significant adverse parameter in MGUS-L MM, but it identified a group at high risk among patients with non–MGUS-L MM.