XIAP and retinal degeneration: Putative involvement of different types of cell death in pathogenesis of retinal degeneration in rcd1 and xlpra2 is also supported by sustained downregulation of X-linked inhibitor of apoptosis (XIAP) found in rcd1 throughout the peak of photoreceptors death and after, while in xlpra2 decreased XIAP levels were detectable only after the peak of cell death [37].