Fig. 2 shows that representative HCC sera with a positive reaction to NPM1 in ELISA also had strong reactivity in the western blotting compared to the normal sera. The autoantibody to NPM1 in serial serum samples from three HCC patients (case nos. 1–3) was also tested. The western blotting results are shown in Fig. 3. This evidence concerns the gene NPM1 and hepatocellular carcinoma.