Background：

This gene， CYP2B6， 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 phenobarbital. The enzyme is known to metabolize some xenobiotics， such as the anti-cancer drugs cyclophosphamide and ifosphamide. Transcript variants for this gene have been described; however， it has not been resolved whether these transcripts are in fact produced by this gene or by a closely related pseudogene， CYP2B7. Both the gene and the pseudogene are located in the middle of a CYP2A pseudogene found in a large cluster of cytochrome P450 genes from the CYP2A， CYP2B and CYP2F subfamilies on chromosome 19q. [provided by RefSeq， Jul 2008]