GZMB and chronic hepatitis B virus infection: Although we cannot provide formal evidence for the role of GzmB expressed in HBcAg-specific CD8 T cells for elimination of HBV-infected hepatocytes, our finding that GzmB levels are increased in HBcAg-specific CD8 T cells after successful control of HBV-infected hepatocytes supports the notion that GzmB could be employed as biomarker for immune control of HBV-infection in future immune monitoring strategies during therapeutic vaccination against chronic hepatitis B. GzmB has been identified as essential downstream effector molecule for T cells to control viral infection28.