Researchers at St. Jude Children's Research Hospital have used genetic manipulation to regenerate auditory hair cells in adult mice, marking a possible advance in treatment of hearing loss in humans. Loss of auditory hair cells is a leading cause of hearing loss and long-term disability in adults worldwide. By manipulating genes, the researchers induced supporting cells located in the inner ear of adult mice to take on the appearance of immature hair cells and to begin producing some of the signature proteins of hair cells. The scientists also identified a genetic pathway for hair cell regeneration and detailed how proteins in that pathway cooperate to foster the process.