Normal digestion is partially facilitated by the function of ABCG8 and its counterpart ABCG5, which together form a heterodimer which transports cholesterol out of the liver and into bile. Subsequently, cholesterol is eliminated from the bodies of healthy individuals. However, in cases of insulin resistance, this functionality is impaired, and digestion does not result in complete elimination of harmful cholesterol. Unsurprisingly, mutations in ABCG8 can lead to gallstone disease, biliary cancer, hypercholesterolemia and atherosclerosis. In studies related to diabetes, heart disease, and digestive cancers, ABCG8 is commonly assessed for normal expression, function and interaction with ABCG5.