According to a new study led by researchers from NYU Grossman School of Medicine, certain stem cells have a unique ability to move between growth compartments in hair follicles,  but  get stuck as people age and so lose their ability to mature and maintain hair color, a new study shows. The new study focused on melanocyte stem cells, or McSCs, in the skin of mice and also found in humans. Hair color is controlled by whether nonfunctional but continually multiplying pools of McSCs within hair ...