Blinatumomab, a bispecific CD19-directed CD3 T-cell engager, has been approved by the US Food and Drug Administration (FDA) since December 3, 2014, for the treatment of MRD-positive B-cell precursor ALL, relapsed or refractory B-cell precursor ALL, and B-cell precursor ALL in the consolidation phase in both adult and pediatric patients [7]. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.