4,5-Dianilinophthalimide (DAPH-1) is an inhibitor of human Epithelial growth factor (IC50 0.3 microM). It was originally developed by scientists at CIBA-Geigy Limited as a potential anti tumor compound, although certain early in vivo studies have been retracted. DAPH-1 was found to be rapidly metabolized in the liver, however, a fluorinated analog (DAPH-2) was more stable in vivo. More recently DAPH-1 has found interest as an anti-amyloid compound. DAPH-1 shows specific efficacy against the yeast prion and may be a useful model for the development of other anti prion compounds.