Human linear chromosomes terminate with telomeres consisting of tandemly repeated DNA sequences and several binding proteins. Because of the end replication problem, telomeric sequences are lost with each cell division. Telomerase is ribonucleoprotein reverse transcriptase enzyme complex that almost all cancer cells acquired to stabilize telomere length and extend their life-span. Measurement of telomere length and telomerase activity might be useful to monitor disease condition in haematological neoplasias.