<qa>  What is the major end-point of hepatitis B reactivation inStudy end-points: The major end-point: hepatitis B reactivation in NHL patients---defined by higher than 10-fold increase of serum HBV DNA level andor reappearance of HBeAg in the serum during and within 6 months after chemotherapy. The minor end-point I : events of hepatic failure and death---defined by jaundice with hepatic encephalopathy. The minor end-point II: the response rate and survival rate in HBsAg-positive NHL patients receiving lamivudine prophylaxis and treatment. 