- Heparin-treated, v-myc-transformed chicken heart mesenchymal cells assume a normal morphology but are hypersensitive to epidermal growth factor (EGF) and brain fibroblast growth factor (bFGF); cells transformed by the v-Ha-ras oncogene are refractory to EGF and bFGF but are hypersensitive to insulin-like growth factors. Balk, S.D., Riley, T.M., Gunther, H.S., Morisi, A. Proc. Natl. Acad. Sci. U.S.A. (1985)