This mouse cochlea section shows three rows of outer hair cells (OHCs) stained for a motor protein called prestin (green). Prestin mediates OHC electromotility, which supports mammalian hearing. Satoe Takahashi and colleagues created two transgenic mouse lines to explore the consequences of prestin mutations associated with a recessive form of hearing loss (nonsyndromic sensorineural hearing loss). These mutations lowered prestin's expression, which resulted in 70–80% reductions in OHC electromotility. However, hearing threshold shifts were minor at lower sound frequencies, suggesting it may be possible to improve prestin-related hearing loss without fully restoring OHC electromotility. See the article by Takahashi et al. for more information. Cover image: Satoe Takahashi