CD19 and precursor B-cell acute lymphoblastic leukemia: As the loss of CD19 was the main limitation in using anti-CD19-CAR-T-cell therapy, to overcome this limitation, blinatumomab (a BiTE composed of a CD3 and a CD19 site) was combined with anti-CD19 CAR-T cells and tested in relapsed/refractory B-ALL cases, and the findings showed that blinatumomab augmented CAR-T performance [166].