Retinal degeneration in the rd10 mouse was accompanied by an increase of α2M, selectively located to the photoreceptor segment (Figures 2b and c and Supplementary Figure 2) and presumptively expressed by Müller glia cells,35 whose role in retinal neurodegeneration has been recently characterized in detail.22, 24α2M binds to proNGF conferring resistance to processing and increased activity on p75NTR. Here, A2M is linked to retinal degeneration.