DKK1 and neoplasm: Studies have shown that DKK1 mRNA and protein expression are higher in rat HCC cancer tissues than in normal liver or adjacent tissues, and overexpression of DKK1 in human liver cancer cell nude mouse xenografts can promote tumor growth and metastasis, suggesting that DKK1 can promote liver cancer cell proliferation and migration,[6] but how DKK1 is overexpressed in liver cancer cells is currently less studied.