PDE6B and retinal degeneration: In this study, we used HC-depleted retinal degeneration mice (rd1) and Islet1−/− genome-edited ROs (gROs) that contain HCs but not rod BCs and showed that host HC deficiency did not alter the number of host BC-graft PR synapses after transplantation into rd1, while the restored light sensitivity was enhanced in the context of host HCs.