It starting to look like we know more about it. A new study suggests that the cause of gray hair is due to a certain type of stem cell getting “stuck” in the hair follicles. The study was conducted by examining the cells in the skin of mice, and it found that melanocyte stem cells are more mobile than previously thought. It is believed that moving melanocytes to the proper location in the hair follicle could help prevent hair from going gray. Further research is needed to understand how melanocyte stem cell localization is regulated.