Clinical data show that elevated BMP4 mRNA expression on leukemic blasts at diagnosis is associated with poor outcomes. (A) Using a cutpoint of 18 AU for the entire cohort (n = 114; EFS values from 1 BMP4^low patient was not available), 5-year EFS was reduced in patients with high BMP4 expression levels on leukemic cells (P = .087; log-rank test). (B) Kaplan-Meier survival curve shows that, for low/intermediate risk patients with BCP-ALL (n = 94), the cutpoint of 18 AU identifies patients with significantly reduced EFS (P = .026; log-rank test). Significant differences between both survival curves were observed from day 730 (shown by an arrow; P = .05; test of proportions). (C) Kaplan-Meier survival curves for the entire validation cohort (n = 236) and (D) low/intermediate-risk patients with BCP-ALL (n = 210) show similar results.