CYP7A1 and gallstones: A substantial amount of evidence dating back as far as 1975 [42], along with more recent evidence, has demonstrated that a deficiency in CYP7A1 [43], genetic variations in the CYP7A1 gene [44], and the inhibition of CYP7A1 with lipid lowering drugs such as fibrates [45], result in increased cholesterol excretion in bile, which increases the risk of gallstone formation [22,26].