PCNA and hepatocellular carcinoma: Moreover, pathological analyses revealed that the higher expression level of PCNA always companied with the higher-grade malignancy of liver tumours derived from both humans and zebrafish (Fig. 5f), suggesting that the mechanisms underlying hepatocarcinogenesis might be identical in zebrafish and humans and that this zebrafish model with various mutations might be helpful for precisely predicting prognosis and malignancy in HCC patients with different mutational spectra.