When HCC patients were compared to non HCC patients, the area under curve (AUC) for OPN (0.51; 95 % CI: 0.39–0.63) was lower than that of AFP (0.79; 95 % CI: 0.70–0.89), suggesting a non superior accuracy to AFP for the diagnosis of HCC. The gene discussed is SPP1; the disease is hepatocellular carcinoma.