An example of the consortium moving into phase II, this project will deliver into the embryonic inner ear of mice genes that could regulate hair cell regeneration; these genes will be in an inactive state. Delivery of an activating molecule in the mature inner ear will then allow that gene to be expressed an appropriate time relative to hair cell damage. While this delivery method is not appropriate for any eventual therapy, it will allow us to examine to determine whether any specific molecules are capable of triggering hair cell regeneration in the mouse.