Study on the composition of deer's periosteal cells

Antler is the mammalian organ that can regenerate. The main components of the deer face are stem cells, but antler only grows on specific parts of the face, so what causes this characteristic? What is the molecular mechanism of antler growth? Therefore, we took samples of the areas where antler does not grow on the deer face, and samples of the areas where the antler grows at a series of time points during the antler growth process to study its mechanism