LRG1 and cholangiocarcinoma: Indeed, we have previously reported a combination of serum CA19-9, leucine-rich a2 glycoprotein 1 (LRG1) and interleukin 6 (IL6) that was capable of discriminating CCA from benign biliary strictures with an area under the receiver operating characteristics (ROC) curve (AUC) of 0.98, and independently of elevated bilirubin [21].