In cerebral ischemia, it has been observed that the γδT cells, a distinct T cell type, are the major IL17-producing cells (88), and the activation of these cells is the primary response to ischemia, which further activates matrix metalloproteinase, pro-inflammatory cytokines, and chemokines that are involved in aggravation of the ischemia–reperfusion injury. This evidence concerns the gene IL17A and ischemia.