Circulating total CK18 concentrations in this study were relatively high compared with prostate (Kramer et al, 2006) and breast (Olofsson et al, 2007) cancer and comparable with those of other gastrointestinal malignancies (Scott et al, 2009) and non-small-cell lung cancer (Hou et al, 2009). Here, KRT18 is linked to non-small cell lung carcinoma.