English: Schematic overview of the orchestrated response to a peripheral nerve injury. Nerve cut generates a gap between the two cut ends, and the distal one progressively degenerates. Repair Schwann cells (SC) (green) in the distal stump, activated by signals coming from the degenerating axon (yellow), are responsible for the clearance of nerve and myelin debris, the recruitment of macrophages (purple), and the secretion of neurotrophic factors. Within a few days, a bridge forms to reconnect the two stumps. Signals from endothelial cells (red), fibroblasts (blue), and macrophages guide collective and oriented SC migration through the bridge, allowing proper axonal re-growth.