CD19 and acute lymphoblastic leukemia: Blinatumomab, also known as Blincyto, is a CD3 × CD19 bispecific T-cell engager (BiTE) and won the approval of the FDA in 2014, for the treatment of acute lymphoblastic leukemia (pre-B-ALL), marking the milestones of the therapeutic utility of the bispecific antibody (bsAb) in cancer immunotherapy.