The sequence of the scFvCD19 was taken from the CD19‐CD3 bispecific antibody Blincyto, which is the first FDA‐approved BsAb for use in cancer immunotherapy.10 The scFvCD3 sequence used here is from the anti‐CD3 mAb OKT3.22 The scFvs, all containing a free cysteine at the C‐terminus (scFv‐C) for DNA conjugation, were expressed in Escherichia coli as a C‐terminal fusion component to the polyhistidine‐tagged maltose binding protein (H6‐MBP). The gene discussed is CD19; the disease is cancer.