In summary, by showing evidence of its role in regulation of ischemic brain injury in a mouse model of stroke, we have identified Itgal as one of possibly many quantitative trait genes for Civq1. Natural DNA sequence variation in Itgal generates qualitative and quantitative change of the transcript and the encoded protein, and a knockout allele, even while retaining one of the newly described splice isoforms, shows a robust effect on infarct volume in vivo and in vitro. Here, ITGAL is linked to Stroke.