ABCB4 and gallstones: The management of large and/or multiple CBD stones requires usually endoscopic sphincterotomy followed by balloon dilation.1 Biliary stenting is associated with a reduction in the number and size of CBD stones.2 Studies have identified multiple potential gene mutations responsible for gallstone formation, such as CYP7A1, ABCB4, and AOPE. 3 Their role in promoting gallstone development in humans is still not fully understood.