Prognostic significance of the subgroups based on gene expression profiles of bone marrow CD34⁺ cells. (A) Rates of overall survival in the 2 subgroups for the training set of bone marrow CD34⁺ cell samples. (B) Cumulative incidence of leukemic transformation in the 2 subgroups for the training set of bone marrow CD34⁺ cell samples. The patients who had already developed leukemia at the time of sampling were removed from the analysis.