GNAT1 and retinitis pigmentosa 1: Although, it appears unlikely at first glance that transplanted PPCs will successfully integrate into degenerated retinas of such affected patients (this study and [20], [21]), a recent study demonstrated that following transplantation into a slow degeneration mouse model of RP (i.e. Gnat1−/− mice), PPCs are able to integrate into the host ONL and functionally connect to the neural circuitry by forming active synapses with endogenous interneurons [13].