CD19 and acute lymphoblastic leukemia: Thereafter, blinatumomab (Blincyto®), a CD19 × CD3 BiTE, gained accelerated FDA-approval for the treatment of relapsed and/or refractory (R/R) acute lymphoblastic leukemia (ALL), and numerous other BiTE candidates are currently in phase I clinical trials for the treatment of various cancers (Przepiorka et al., 2015).