In eukaryotic cells, DNA-encoded genetic information is packaged into a chromatin polymer, which must be opened to allow increased accessibility for gene regulatory factors, or compacted to restrict access of the transcriptional machinery to target genes.In general, these "opened" and "closed" chromatin states correspond to gene activation versus gene repression, respectively.A precise coordination and organization of events in opening and closing of the chromatin is crucial to ensure correct spatial and temporal gene activation/repression and is achieved by the concerted or independent actions of ATP-dependent chromatin-remodelling complexes and histone-modifying enzymes.These chromatin remodelling modifiers have been shown to play critical roles in development, cell differentiation and proliferation by regulating specific gene transcription.Similarly, we have observed that histonc H3 acetylation, methylation and phosphorylation are required for the telomerase gene trans-activation, strongly suggesting a role for chromatin re-configuration in controlling telomerase expression.Evidence has accumulated that the transcriptional activation of the telomerase gene by external signals and transcription factors in both human stem and cancer cells all depends on their attraction of specific chromatin remodelling-modifiers to the telomerase gene promoter.My presentation will focus on recent insights into the telomerase regulation by ehromatin reconfiguration in both normal and malignant human cells.