Figure 4. Glial fibrillary acidic protein (GFAP) activation in the host retina around the grafting site 3 weeks after transplantation. GFAP activation (A) was found in all examined cases where the subretinal grafts were found, regardless of whether the grafts survived or not. In the case shown, the release of human nuclei –positive (HNu [+]) immunoreactivity was found in the grafting site outside of the nuclei, indicating the initial stage of graft destruction (B, C). Inset in C shows a low-power image of the same graft from which the main panel was derived. Panel D displays the staining of nuclei of both human and mouse cells with 4', 6-diamidino-2-phenylindole (DAPI). The scale bar used in panels A-D is 50 μm. The outer nuclear layer (ONL) around the grafting site was damaged by the needle. The asterisk indicates the area shown in the inset. Abbreviations used in this legend are the following: INL, inner nuclear layer; RGC, retinal ganglion cell (layer).