For example, although Hsp90 inhibition with 17-AAG enhances visual function and delays photoreceptor degeneration in both P23H and R135L transgenic rat models of retinitis pigmentosa, the effect of 17-AAG on rod opsin P23H mutant is dependent on HSF1 but its effect on R135L mutant is mediated by a requirement of Hsp90 for rhodopsin kinase (GRK1) maturation and function.15 To overcome the limitation of using chemical compounds, we used a HSF1 transgenic mouse strain that overexpress the human full-length non-mutant HSF1 gene. The gene discussed is GRK1; the disease is retinitis pigmentosa.