这个基因编码细胞色素P450超家族的一个成员。细胞色素P450蛋白是单加氧酶，催化药物代谢和胆固醇、类固醇和其他脂质合成的许多反应。这种蛋白定位于内质网，已知能代谢多达25%的常用药物。其底物包括抗抑郁药、抗精神病药、止痛药和镇咳药、β-肾上腺素能阻滞剂、抗焦虑药和止吐药。该基因在人群中具有高度多态性；某些等位基因导致代谢表型较差，其特征是代谢酶底物的能力下降。一些代谢表型较差的个体没有功能蛋白，因为他们携带2个无效等位基因，而在其他个体则没有这种基因。这种基因的拷贝数可能不同，具有超快速代谢表型的个体可以有3个或更多的基因活性拷贝。另外，还发现了编码不同亚型的剪接转录变体。
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 is known to metabolize as many as 25% of commonly prescribed drugs. Its substrates include antidepressants, antipsychotics, analgesics and antitussives, beta adrenergic blocking agents, antiarrythmics and antiemetics. The gene is highly polymorphic in the human population; certain alleles result in the poor metabolizer phenotype, characterized by a decreased ability to metabolize the enzyme's substrates. Some individuals with the poor metabolizer phenotype have no functional protein since they carry 2 null alleles whereas in other individuals the gene is absent. This gene can vary in copy number and individuals with the ultrarapid metabolizer phenotype can have 3 or more active copies of the gene. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.