INTRODUCTION Human tissue homeostasis is precisely regulated bycellular division,differentiation and death.Normalhuman somatic cells progressively lose telomererestriction fragment(TRF)length with eachsuccessive cell division,eventually leading tocellular quiescence,chromosomal end-degradationand apoptosis.On the contrary,stabilization oftelomere lengths by expressing telomerase,an RNA-dependent DNA polymerase,may be involved incellular immortality and carcinogenesis. INTRODUCTION Human tissue homeostasis is precisely regulated by cellular division, differentiation and death.Normal human somatic cells progressively lose telomererestriction fragment (TRF) length with each successful cell division, eventual leading to cellular quiescence,chromosomal end-degradation and apoptosis.On the contrary, stabilization of telomere lengths by expression, Telomerase, an RNA-dependent DNA polymerase, may be involved in cellular immortality and carcinogenesis.