(A, B) Retinal levels of full-length (p49) and cleaved (p35–p39) caspase-9 are shown after ballistic injury, as assessed by Western blotting showing increased p35–p39 at 5 hours (*P = 0.002) and a nonsignificant increase in p49 at 48 hours (P = 0.136). (C, D) Retinal levels of catalytically active, full-length caspase-9 increased by 5 hours and remained increased at 48 hours after ballistic injury, as detected by bVAD-fmk pull-down assay (*P = 0.047; **P = 0.016). (E, F) Retinal levels of full-length (p55) and cleaved (p18) caspase-8 are shown after ballistic injury, assessed by Western blotting showing no significant change in levels of either p55 (P = 0.246) or p18 (P = 0.103). (G) No catalytically active p55 and p18 caspase-8 were detected by bVAD-fmk pull-down assay (G). (H, I) Caspase-8-positive control. After treatment with TNF-α to induce caspase-8 activity, C6 cells showed increased p18 and reduced p55 levels (*P = 0.026; **P = 0.013). (J) Staining of the of XBIR3 protein, unlinked and linked to Pen-1.