The present invention derives from the discovery that CDC25 phosphatases and Raf proteins are able to physically interact to form protein-protein complexes, with the Raf protein mediating the activation of CDC25 phosphatases. The present invention provides both cell-free and cellular assays for detecting agents which modulate the ras-dependent activation of CDC25, as for example, by affecting the binding of a CDC25 protein with Raf, or Raf-associated complexes. Also disclosed is a method for transforming/immortalizing cells, particularly primary cell cultures.

_ presente invención derivar descubrimiento que CDC25 phosphatases y Royal Air Force proteína ser capaz físico obrar recíprocamente forma protei'na-protei'na complejo, con Royal Air Force proteína mediating activación CDC25 phosphatases. _ presente invención proporcionar ambo sin células y celular analizar para detecting agente que modular ras-dependiente activación CDC25, como por ejemplo, por affecting binding uno CDC25 proteína con Royal Air Force, o Royal Air Force-asociado complejo. _ también divulgar ser uno método para transforming/inmortalizar célula, particular primario célula cultura. _