PTGS2 and chronic hepatitis B virus infection: As shown in Table 1 the serum levels of PGE2 were significantly higher in patients with chronic hepatitis B infection in comparison with healthy control individuals (mean ± SEM 1393.9 ± 834.5 vs. 161.6 ± 79.2 pg/mL P < 0.01), suggesting that HBV infection resulted in upregulation of COX-2.