Both the baseline plasma CK18–Asp396 and CK18 levels were significantly higher in the patients with metastatic disease compared with those with locally advanced disease; CK18–Asp396, median 210 U l−1 (range 58–2535 U l−1) vs 164 U l−1 (range 35–333 U l−1), CK18, median 833 U l−1 (range 260–7747 U l−1) vs 452 U l−1 (range 269–746 U l−1) (P=0.014 and P=0.011, for CK18–Asp396 and CK18, respectively). The gene discussed is KRT18; the disease is metastatic neoplasm.