Ras redux: rethinking how and where Ras acts.

Ras proteins couple surface receptor stimulation to an ever-expanding array of effector pathways. The integrated activities of these signaling pathways result in a range of biological responses depending on cellular context and conditions. Decoding the various inputs that underlie Ras-induced proliferation and transformation, in particular, holds the promise of more effective cancer therapies. Recent findings have provided new and unexpected insights into the predominant pathways Ras employs to transform human cells and the subcellular platforms from which it can act.