TA has a tendency to be higher in relapsed cases of leukemia than in fresh ones. Accumulated expression of TA might contribute to the aggressive biological behaviour and refractoriness of AML at relapse.Elevated TA in AML was correlated with advanced age, with the number of blast cells both in the PB and the bone marrow, with the total WBC count and M1 FAB subtypes. All these parameters are among the poor prognostic factors of AML. Thus elevated TA may be a marker for disease severity. Study of telomerase enzyme and its related subunits remain to be understood and to be mastered, to clarify the biological significance of elevated TA in acute leukemia.The potential uses of telomevase inhibitors for cancer treatment remain promising but await the development of suitable inhibitors for further testing.