Prof.Tong Chunrong and Director Liu Shuangyou spoke at the Presidential Symposium on behalf of the team:"CD19-and CD22 CAR T Sequential Treatment of acute B lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation:With a median follow-up time of 10 months,the study was selected as one of the top six outstanding clinical abstracts from more than 1,000 reviews worldwide.Further clinical studies should be conducted to increase the number of cases and follow-up time:32 patients with B-ALL who relapsed after allogeneic hematopoietic stem cell transplantation were treated with CD19-and CD22 CAR-T sequential therapy.The median observation time was 10 months,and the complete response rate was 84.4%,the overall survival rate was 87.5%,and the minimal residual negative survival rate was 58.3%,which was the highest in the world.