In a search for improved non-invasive diagnostic markers of CCA, we have investigated serum levels of CA19-9, LRG1, IL6, MUC5AC, CYFRA21.1 and PKM2 in a set of samples taken from patients diagnosed with CCA and PSC and tested combinations of these putative markers for differential diagnosis. The gene discussed is LRG1; the disease is cholangiocarcinoma.