DKK2 and hepatocellular carcinoma: Of these variations that were associated with HCC, four that belong to the human DKK2 gene were of particular interest due to their location within the regulatory region of the gene; these consisted of three in the promoter region (g.-967A>T, g.-923C>A, and g.-441T>G) and one in the 5’UTR (c.550T>C).