Although the expression of Cyp1a2 was significantly downregulated and the pericentral lobular area with hepatocytes expressing Cyp1a2 was decreased by almost 90% in cirrhotic mouse livers, the formation of paraxanthine was not decreased in cirrhosis, and the AUC of the parent compound caffeine even decreased. The gene discussed is CYP1A2; the disease is Cirrhosis.