Fig. 3.

Off-target effects of transductionally bispecific toxin conjugates. A cartoon showing the various cellular interactions of bispecific toxin conjugates harboring two receptor-targeting ligands (blue and red). Since binding by each ligand to its targeted receptor is independent, and each receptor is capable is endocytosis, intoxication ensues in all cells harboring one or both of the targeted cell-surface receptors. Activity in normal cells harboring only one of the targeted receptor leads to off-target, dose-limiting toxicity