This study examined the efficacy and adverse effects of CD19 chimeric antigen receptor(CAR) T cells against ALL in the CNS using a xenograft mouse model. Mouse model has been administrated either by intravenous or intracerebroventricular delivery of CAR T cells. Partial effects were observed when piggy bac CD19 CAR T cells were injected through intravenously. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.