A week. According to the public health network, cart will last for a week after blood transfusion, and it will react from the fifth day to the seventh day. Some people don't have a fever from beginning to end. Cart is used to treat acute lymphoblastic leukemia, chronic lymphoblastic leukemia and other diseases. Cart therapy is a commonly used treatment or adjuvant therapy for hematological malignancies. After modifying their own T cells, they are transfused to patients, and finally achieve the purpose of treating related diseases, which is of great significance for the treatment of hematological malignant tumor diseases.