ABCB1 and acute myeloid leukemia: Moreover, strong positive correlations were found between MDR1 mRNA expression levels in the tumor cells of AML patients in cohort 1 and response to therapy (r = 1.0), as well as aberrant immunophenotype of tumor cells (r = 0.73) and standard prognosis stratification (r = 1.0); however, p was >0.05.