CYP2C9（cytochrome P450 family 2 subfamily C member 9），癌症关联基因，基因ID：1559，该基因编码细胞色素p450酶超家族的一个成员。细胞色素p450蛋白是一种单加氧酶，催化药物代谢和胆固醇、类固醇等脂类的合成。该蛋白定位于内质网，由利福平诱导表达。众所周知，这种酶能代谢许多外源性物质，包括苯妥英钠、甲苯磺脲、布洛芬和s-华法林。鉴定苯妥英钠和甲苯磺丁胺代谢不良个体的研究表明，该基因具有多态性。该基因位于10q24号染色体上的细胞色素p450基因簇内。[由RefSeq提供，2008年7月]This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol， steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by rifampin. The enzyme is known to metabolize many xenobiotics， including phenytoin， tolbutamide， ibuprofen and S-warfarin. Studies identifying individuals who are poor metabolizers of phenytoin and tolbutamide suggest that this gene is polymorphic. The gene is located within a cluster of cytochrome P450 genes on chromosome 10q24. [provided by RefSeq， J。