Notably, these IC50 values are relatively comparable to those obtained in cancer immunotherapy: the anti-EGFR(scFv) immunotoxins; scFv1711-ETAʹ and scFv2112-ETAʹ developed by Niesen et al., for the treatment of solid tumours demonstrated IC50 values ranging from 4 pM to 0.46 nM [45]. Here, EGFR is linked to cancer.