Some of molecular markers such as mutations in fms-related tyrosine kinase-3 (FLT3), nucleophosmin (NPM1), CCAAT/enhancer binding protein alpha (CEBPA) and runt-related transcription factor 1 (RUNX1) gene have made an impact on prognosis of AML-NK patients, and have already been included into the revised World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia, and European LeukemiaNet (ELN).2,3 However, there is a constant need for the introduction of new molecular markers that have significant impact on the prognosis of patients. The gene discussed is FLT3; the disease is acute leukemia.