CD109 and pancreatic neoplasm: While the soluble recombinant form of CD109 was reported to be capable of binding to TGF-β and antagonising TGF-β signalling and cellular responses in experimental system [42, 43], it remains unclear whether patients with pancreatic cancer or any other cancer type shed CD109 antigen into their sera and any other body fluids and if so, whether CD109 may confer diagnostic, prognostic and predictive values, and therefore warrants further investigation.