Time to progression in MGUS and SMM according to the percentage of immunophenotypically aberrant plasma cells. (A) For MGUS, the median time to progression (TTP) was 107 months versus not reached (nr) for patients with 95% or greater versus less than 95% aberrant PC, respectively (P < .001). (B) For SMM, the median TTP was 34 months vs not reached for patients with 95% or greater versus less than 95% aberrant PC, respectively (P < .001).