Mak LY, et al. - The virological aspect and clinical application of hepatitis B core-related antigen (HBcrAg) with respect to the natural history and treatment of chronic hepatitis B (CHB) were examined. The researchers concluded that HBcrAg was a potential surrogate marker of covalently closed circular DNA (cccDNA). In the case of disease monitoring as well as for the prediction of the treatment response and disease outcome of chronic hepatitis B, it could become a useful marker.