ＣＹＰ２Ｅ１基因是ＣＹＰ４５０大家族主要成员之一，是致癌物亚硝胺类代谢活化的主要酶类，不同程度地表达于肝脏和许多肝外组织，与亚硝胺类多部位致癌作用密切相关。该基因定位于１０ｑ２４．３－ｑｔｅｒ，其表达调节受多种因素的影响。ＣＹＰ２Ｅ１基因存在多个限制性内切酶长度多态性（ＲＦＬＰ）。ＲＦＬＰ与人类肿瘤易感性有密切关系 CYP2E1 gene is one of the major members of the CYP450 family, and is the main enzyme for the metabolic activation of carcinogenic nitrosamines. It is expressed to varying degrees in the liver and many extrahepatic tissues. It is closely related to the carcinogenesis of multiple sites of nitrosamines. This gene is localized to 10q24.3-qter and its expression regulation is affected by many factors. There are multiple restriction endonuclease length polymorphisms (RFLPs) in the CYP2E1 gene. RFLP is closely related to the susceptibility of human tumors