We fused the L010 exotoxin A domain to the C terminus of a dimeric EGFR targeting affibody domain (Z2), as the free C terminus of the exotoxin is crucial for cytotoxic activity, with the intent that the Z2-LO10 construct could target and kill tumor cells that overexpress EGFR such as certain breast cancers and gliomas75,76. This evidence concerns the gene EGFR and breast cancer.