The accurate monitoring of the boundary between cirrhosis and hepatoma using appropriate signals is the key to the success of surgery.2,3 To obtain excellent differentiated signals, previous research has used many different biological enzymes, because they show abnormal and different expression activities, during the process of hepatopathic deterioration.4,5 Among them, cyclooxygenase-2 (COX-2) and N-acetyltransferase (NAT) are attractive targets due to their involvement at all stages of the disease from the earliest inflammatory phase to the premalignant and malignant phase. The gene discussed is PTGS2; the disease is hepatocellular carcinoma.