A couple of things we can learn from this:
1) They were researching something else -- a neurological issue which was unrelated to hair -- when they discovered this. Dr. Terskykh at Sanford Burnham was also researching a neurological issue when he made his discovery. (Note: embryologically, the development of hair follicles comes partly from the neural ectoderm, the same embryonic cells which give rise to the nervous system -- so, believe it or not, your hair and your nerves are related.) The fact that so many hair loss related discoveries come from research into other systems of the body shows that PRIMARY hair loss research is underfunded. (Remember, Rogaine came from a drug used to treat high blood pressure).
2) True, we don't know if what exists in mice is the same as what exists in humans. Most likely, there is an ANALOGOUS protein, similar but not with an identical peptide sequence. But at least now someone will (hopefully) look for the analogous human protein and try to sequence it. That will take a while. Unfortunately, the mouse protein itself will probably not work in humans.
3) Here's a video --