Based on the up-regulated expression levels of S100A6 in human and murine CCA tissue samples and the available data suggesting a role for S100A6 in the pathophysiology of various gastrointestinal cancers, including the potential use of serum S100A6 levels as diagnostic biomarker, we next analyzed serum levels of S100A6 in a large and well characterized cohort of 112 patients with CCA and compared them to healthy controls (patients characteristics are given in Table 1). The gene discussed is S100A6; the disease is cholangiocarcinoma.