Nerve cells in the body’s periphery, for example in arms and legs, can regrow after injuries. Unfortunately for victims of stroke and spinal cord injuries, cells in the central nervous system can’t. Researchers now have used bioinformatics methods to find a network of genes that triggers self-repair in the peripheral nervous system. They used that network to identify a small molecule that can encourage regeneration in a central nerve in mice (Neuron 2016, DOI: 10.1016/j.neuron.2016.01.034). Vijayendran Chandran and Daniel H. Geschwind of UCLA and their colleagues identified the components of the network by finding groups of genes with expression levels that increased or decreased together over time after various injuries to peripheral nerves in rodents. Next, they analyzed a publicly available database of gene expression patterns triggered by about 1,300 biologically active small molecules. They looked for the compound with a pattern that best matched the one observed in their gene network. The result was ambroxol, a drug that helps clear mucus in the lungs. When given to mice with optic nerve lesions, the compound induced a modest level of neuron regrowth.