The authors retrospectively assessed serum DKK1 in 1284 patients (633 with HCC, 171 with chronic HBV infection, 168 with cirrhosis, and 312 healthy controls) and found that DKK1 has better diagnostic value for HCC than does AFP, especially for patients with AFP-negative and early stage HCC. The gene discussed is DKK1; the disease is hepatocellular carcinoma.