Induced hypothermia has been shown to attenuate MMP-9 expression in rodent TBI and stroke models, but, as yet, this phenomenon has not been investigated in human patients.25,26 Despite a number of randomized trials, therapeutic hypothermia has not been conclusively shown to improve outcome post-TBI, though its use to control ICP remains widespread.11,27,28 Conceivably, targeting hypothermia to patients with increased MMP-9 expression may be a method to select the subgroup of patients in which the benefits of this treatment outweigh its deleterious effects. This evidence concerns the gene MMP9 and stroke disorder.