The quantification of serum HBsAg has recently been advocated as a marker of disease monitoring for CHB [10]. Low levels of serum HBsAg are associated with good immune control of the hepatitis B virus (HBV), with serum HBsAg levels of 100-200 IU/mL being predictive of eventual HBsAg seroclearance in treatment-naïve CHB. Nonetheless , in the abovementioned multicenter prospective study, only 4.8% and 14.1% of study subjects had HBsAg levels <100 IU/mL or <200 IU/mL at the point of treatment cessation - which could explain the study's high rate of disease relapse. In contrast, in another study of retrospective nature which found a lower relapse rate of 66%, 27.6% of patients had HBsAg levels <200 IU/mL at treatment cessation.