CD44 expression correlates with CXCR4 in cells of patients with AML. (A) CXCR4 cell surface expression of primary AML cells from patients with different prognoses was determined via flow cytometry (1-way analysis of variance [ANOVA] with Bonferroni posttest). (B) Cell surface expression of CD44 and CXCR4 was correlated (n = 39; Pearson’s correlation test r = 0.3971; P = .012). (C) Serum CXCL12 level of AML patients (n = 12) as well as healthy donors (n = 15) was measured by enzyme-linked immunosorbent assay (ELISA) (Student t test P = .0003). MFI, mean fluorescent intensity. *P ≤ .05; ***P ≤ .001. The error bars indicate standard deviation.