At this late age, rd1 mice represent a relevant model for studying transplantation in patients with end stage RP, as in rd1 mice there is sever structural degeneration of the ONL, as appose to other retinal disease models such as the CRX knockout mouse, in which the retina is severely compromised functionally, but there is no structural degeneration. The gene discussed is CRX; the disease is retinitis pigmentosa 1.