Numerous studies on telomerase expression have consistently demonstrated the presence of telomerase activity in the vast majority of different types of cancer, as well as immortalized cells, but have failed to detect telomerase in most normal tissues (1). Examples include breast cancer, neuroblastoma, and cervical cancers, in which a correlation between telomerase expression and staging or clinical outcome has been demonstrated (2). Therefore, its very restricted, tumor-specific expression pattern makes telomerase an attractive target for diagnostic and prognostic purposes and for therapeutic intervention in a variety of human cancers