Looking for new sources of multipotent stem cells? Try dandruff. Researchers at the University of Pennsylvania School of Medicine have found that hair follicles are a rich source of adult stem cells which can be differentiated into nerve cells, smooth muscle cells and skin pigment cells. They say that if their approach to isolating and growing the cells can be upscaled, it might some day provide the tissue needed for disorders like peripheral nerve disease, Parkinson's and spinal cord injury. The results were published in the American Journal of Pathology.