Ras pathway

[jello22]

1)When epidermal growth factor is added to epithelial cells, the Ras and Raf proteins are both acitivated. From this observation by itself, what conclusion can you draw about the relationship between Ras and Raf?
2)In mutant cells containing a permanently activated Ras protein, addition of EGF does not activate the Raf protein as much as it does in normal cells. What conclusion can you draw from this observation?

Help will be greatly appreciated.

[mith]

1. Depends on what you mean by activated. Usually, an increase of expression means nothing.