New hair from healing wounds

In mammals, most wounds heal by repair, not regeneration. It now seems that, as they heal, open skin wounds in adult mice form new hair follicles that follow similar developmental paths to those of embryos. The mammalian hair follicle is thought to form anew only during development, and loss of an adult follicle is generally considered permanent. Fifty years ago in Nature, Billingham and Russel reported 'hair neogenesis' in rabbit skin, but this was later discounted. Now it is back, with the discovery that hair follicle regeneration is triggered by wounding the skin of adult mice. This suggests that mammalian skin responds to wounding with greater plasticity and regenerative capacity than was previously believed, and has implications for those studying wound healing, tissue regeneration and stem cell function.