In contrast, after a controlled cortical impact (CCI), a model of focal TBI, elevated levels of p-PERK have been observed at 3 h,27 12 h,29 24 h,29 and 25 days post-injury.16 Activation of mediators downstream of PERK were also found to differ between injury models.16 Levels of p-eIF2α were increased at 25 days post-CCI,16 elevated from 12 to 72 h after subarachnoid haemorrhage,13 and raised from 4 to 48 h after intracerebral haemorrhage.28 This evidence concerns the gene EIF2AK3 and subarachnoid hemorrhage.