Abstract
Background and Objectives
Chronic Myeloid Leukemia (CML) is a clonal disorder of the hematopoietic stem cell caused by the BCR-ABL receptor tyrosinkinase. The tumour suppressor gene of  P16 plays the key role in the cell cycle control. The inactivation of this gene is associated with tumorgenesis, pathogenesis and progression of leukemia. The aim of this study was to evaluate the expression of P16 gene in patients with chronic myeloid leukemia for the identification of the gene expression changes so that the role of the gene in diagnosis and treatment of the disease could be determined.
Materials and Methods
In this descriptive study, the expression of P16 gene in 40 CML patients in chronic phase and 8 healthy subjects as the control all in Payvand Medical Laboratory was examined by Real Time PCR technique. Results were analyzed using the Relative Expression Software Tool (REST2009).
 
Results
P16 gene expression was significantly down-regulated in 32 patients (p ≤ 0.05), and up-regulated in 8 patients (p ≤ 0.05) compared to the control group.
 
Conclusions 
In conclusion, downregulation or upregulation of P16 may be of importance in the biology of CML.Other studies are also required to elucidate the exact function of this tumor suppressor in cancer.