In contrast to low or no DKK-1 expression in normal cells or tissue as shown in this study, several HCC cell lines had high DKK-1 expression, and the serum level of DKK-1 in HCC patients is significantly associated with HCC staging, HCC recurrence after curative resection, and poor prognosis [9, 17]. This evidence concerns the gene DKK1 and hepatocellular carcinoma.