CXCL12 and ischemia: It has been proposed that CXCL12 via its CXCR4 receptor plays a role also in regulating the survival and migration of NSCs in response to CNS trauma, such as brain tumors, ischemia, and neuroinflammation-associated disorders [13, 16–20], and in regulating the migration and survival of OPCs in vitro [26, 27].