Our research is focused on the mechanosensory hair cells that are the receptor cells of hearing and balance. Specifically, we are interested in the molecular signals that regulate the survival, homeostasis, and death of these cells. Mammalian hair cells are terminally differentiated and are not regenerated when they are lost. Therefore, human hair cells must survive and function for up to a century (or longer) in order to transduce sound and head movement into the neural signals of hearing and balance throughout a normal lifespan. During this lengthy period of time, the hair cell may encounter multiple potentially-toxic stimuli, including exposure to excessive sound and/or exposure to therapeutic drugs with ototoxic side effects. Hair cells must be able to respond rapidly and effectively to these and other potentially-cytotoxic stimuli if they are to survive and continue to function.