VPA response and outcome prediction. (A) - (C) Kaplan-Meier survival estimates according to CXCR4 and LBH expression. AML cases with high CXCR4 expression levels (4th quartile) were associated with a significantly longer relapse free survival (RFS, median survival not reached vs. 339 d, P = 0.0496) (A), as opposed to low LBH expression (1st quartile) cases, who showed an inferior RFS (median survival 261 vs. 474 d, P = 0.0464) (B). Notably, there was no overlap between prognostically favorable 4th quartile CXCR4 high expression and LBH 1st quartile low expression cases. In accordance, a comparison of samples based on these respective quartiles showed also a significant difference in RFS (median survival not reached vs. 261 d, P = 0.0182) (C).