ABCB1 and neoplasm: Our study demonstrates that the developed prognostic scale for the risk stratification of AML patients based on cell sensitivity to chemotherapeutic drugs, MDR1 mRNA expression, tumor origin (primary or secondary), unfavorable cytogenetic abnormalities, and aberrant immunophenotype is related to the therapy response and represents an independent predictive factor for the overall survival of newly diagnosed AML patients without complicated clinical and hematological anamnesis.