RogerRoast writes An article published in the journal Cell, molecular signals from fat cells (adipocytes) precursors under the skin are needed to stimulate hair growth in mice. Yale researchers report in the newspaper that these cells produce molecules called PDGF (platelet derived growth factor), which are required to produce hair growth. The discovery of the source of signals that trigger hair growth can lead to new treatments for baldness. The trick is to obtain precursors of adipocytes under the skin of about stem cells at the base of the hair follicles.