EGF and breast adenocarcinoma: Possibly one of the most promising methods for saporin-based targeted toxin augmentation was first described by Heisler et al. [5] who demonstrated that saponins from Gypsophila plant species increased the cytotoxicity of epidermal growth factor (EGF)-saporin for the EGF+ human breast adenocarcinoma cell line MCF-7 and EGF transfected NIH-3T3 cells by several thousand-fold.