Chiu YM, et al. - This article was written with the objective to assess the relative risks of developing liver enzyme elevation in anti-TNF users with differing hepatitis B virus (HBV) infection status. The outcome revealed that the HBsAg+ patients with immune-mediated diseases who received anti-TNF therapy had an approximately eight-fold higher likelihood of liver enzyme elevation than those without HBV infection, whereas patients with HBsAg–/HBcAb+ serostatus had a risk similar to that of uninfected patients.