Taken together, our results suggest that Mdm1 deficiency causes defects in specific IFT, resulting in an imbalance between continuous replenishment of OS discs via the CC in photoreceptor cells and the simultaneous phagocytosis of the OS by RPE cells, leading to apoptosis in the ONL and causing retinal degeneration (Fig. 6d). The gene discussed is SAXO6; the disease is retinal degeneration.