Heme oxygenase-1(HO-1)is a type of stress related gene,which harbors the ability of anti-inflammatory,anti-apoptosis,anti-oxidation and drug resistance.In physiological status,the expression of HO-1 gene in human normal tissues is extremely low.When subjected to a constant stimulation of alcohol,spicy and hot,over expression of HO-1 gene in the related tissues is often observed.In tumor tissues,the abnormal expres-sion of HO-1 is closely related to their biological behaviors.In recent years,there is a trend to believe that the gene polymorphism and its metabolic products( bilirubin,Fe2+,CO) involve in the decomposition of heme partici-pate in the activation of many signaling pathways,and affect the initiation and development of tumor diseases.In addition,the expression level of HO-1 gene is up-regulated in many tumor diseases,which can not only affect the growth and proliferation of tumor cells by regulation of the oxidative stress levels of tumor microenvironments, but also induce the tumor cells to produce drug resistance.Therefore,the abnormal expression of HO-1 may be involved in the initiation and development processes of tumors.