Preoperative biliary stenting and concurrent liver function were also investigated in the interpretation of CK18 levels, as obstructive jaundice has been shown to be a confounding factor in proteomic studies (Yan et al, 2009) along with effect of plasma storage duration (Cummings et al, 2007; Greystoke et al, 2008). Here, KRT18 is linked to obstructive jaundice.