CD19 and acute lymphoblastic leukemia: Among 110 patients with CD19-positive R/R BCP ALL (aged >28 days up to 18 years) enrolled in the study, 69 achieved CR within the first two treatment cycles; most of them (73.5%) received an allogeneic HSCT and had better OS compared with those who did not (1-year OS probability: 87% vs. 29%).