Fig. 4. **Detection of E-RAF in human breast cancer biopsy.**

If what I discussed in the previous paragraph regarding the brain derived regulator of E-RAF gene expression is proven correct, it is possible to suggest that defects in this regulatory protein mechanism and its action could lead to uncontrolled expression of the E-RAF gene. How does this enhanced expression of E-RAF gene influence mammary cancer progression remains to be seen. One of the major molecular targets of progesterone bound E-RAF is the collagenase gene. Whether the progesterone bound E-RAF mediated enhancement in collagenase gene expression has any role in mammary cancer metastasis is yet to be examined.
