ERBB2 and neoplasm: Built on the IgG-[L]-scFv format, we generated homodimeric EGFR and HER2 T-BsAbs (referred to otherwise as EGFRxEGFR and HER2xHER2 T-BsAbs respectively) which utilize scFv domains fused to the C-termini of each light chain to engage CD3 on T cells while retaining bivalent binding of the tumor targets with both Fab arms.