Astrocyte scar formation promotes CNS axon regeneration. A study in Nature (2016) challenges the long-held belief that astrocyte scars prevent axon regeneration in the central nervous system (CNS). Using genetically modified mice, the researchers found that preventing astrocyte scar formation or deleting chronic scars did not lead to spontaneous axon regrowth through spinal cord injuries (SCI). In contrast, delivering specific growth factors and using priming injuries significantly stimulated axon regrowth past scar-forming astrocytes and inhibitory molecules. RNA sequencing revealed that both astrocytes and non-astrocyte cells in SCI lesions express multiple axon-growth supporting molecules. The study shows that astrocyte scars, contrary to previous assumptions, aid rather than hinder CNS axon regeneration. The findings suggest that astrocyte scars may play a supportive role in axon regeneration, and that the presence of scar-forming astrocytes is critical for maintaining tissue integrity. The study also highlights the importance of growth factors and the role of laminin in axon regrowth. The research has important implications for CNS repair strategies, indicating that astrocyte scars may be exploitable bridges for regrowing axons across severe CNS lesions.Astrocyte scar formation promotes CNS axon regeneration. A study in Nature (2016) challenges the long-held belief that astrocyte scars prevent axon regeneration in the central nervous system (CNS). Using genetically modified mice, the researchers found that preventing astrocyte scar formation or deleting chronic scars did not lead to spontaneous axon regrowth through spinal cord injuries (SCI). In contrast, delivering specific growth factors and using priming injuries significantly stimulated axon regrowth past scar-forming astrocytes and inhibitory molecules. RNA sequencing revealed that both astrocytes and non-astrocyte cells in SCI lesions express multiple axon-growth supporting molecules. The study shows that astrocyte scars, contrary to previous assumptions, aid rather than hinder CNS axon regeneration. The findings suggest that astrocyte scars may play a supportive role in axon regeneration, and that the presence of scar-forming astrocytes is critical for maintaining tissue integrity. The study also highlights the importance of growth factors and the role of laminin in axon regrowth. The research has important implications for CNS repair strategies, indicating that astrocyte scars may be exploitable bridges for regrowing axons across severe CNS lesions.