11.   The symptoms also suggest that estrogen acts directly on bone cells, rather than through an indirect mechanism, as had been proposed.

12.   There are even toxins that break down bone cells.

13.   They also need cells that would remain brain cells and not revert to fat cells or bone cells, he added.

14.   If bone cells are to grow, they need materials, he said.

15.   That is what the estrogen does to the bone cells.

16.   Unlike BMPs or parathyroid hormone, researchers believe Runx would only affect bone cells and only in small areas.