This disclosure relates to for expand inner ear supporting cell (such as, Lgr5+ inner ear supporting cells) and by inner ear supporting cell (such as, Lgr5+ inner ear supporting cells) be divided into inner ear hair cells (for example, atonality homologue 1 (Atoh1)+inner ear hair cells) method and inner ear hearing sertoli cell and hair cell for example for identifying the purposes of the candidate therapeutic compound for treating hearing loss and balance loss. In addition, methods herein can be used for treating the subject with hearing loss and balance loss, the subject will benefit from the proliferation of inner ear supporting cell (such as Lgr5+ inner ear supporting cells) and the increase of differentiation.