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 endoplasmic reticulum membrane protein catalyzes the conversion of 7 alpha-hydroxy-4-cholesten-3-one into 7-alpha,12-alpha-dihydroxy-4-cholesten-3-one. The balance between these two steroids determines the relative amounts of cholic acid and chenodeoxycholic acid both of which are secreted in the bile and affect the solubility of cholesterol. This gene is unique among the cytochrome P450 genes in that it is intronless.CYP8B1 (Cytochrome P450 Family 8 Subfamily B Member 1) is a Protein Coding gene. Diseases associated with CYP8B1 include Bile Duct Disease and Biliary Tract Disease. Among its related pathways are Synthesis of bile acids and bile salts and NAD metabolism. GO annotations related to this gene include iron ion binding and oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen. An important paralog of this gene is PTGIS.