3. Is there any clinical factor that can reliably predict off-treatment virologic relapse? A potential novel marker is the hepatitis B core-related antigen (HBcrAg), which detects an identical amino-acid sequence shared by HBeAg, hepatitis B core antigen and 22 kDa precore protein . Serum HBcrAg levels reflect the level of HBV disease activity [15], predict the occurrence of liver-related complications , and also correlate well with intrahepatic HBV cccDNA levels , the master intrahepatic reservoir for the production of HBV virions. Low levels of HBcrAg could reflect low levels of intrahepatic HBV cccDNA, meaning a better chance of maintaining off-treatment durability.