In this article, after first briefly reviewing the role of growth factors, particularly insulin-like growth factor-1 (IGF-1), in the inner ear, we summarize the application of IGF-1 to the treatment of inner ear disorders in animal models, the mechanisms underlying the effects of IGF-1 on the inner ear, and a clinical trial of IGF-1 in human SSHL cases. The gene discussed is IGF1; the disease is inner ear disorder.