To compare the gene expressional change between the primarily cultured neurons after OGD and neurons in ischemic stroke model in vivo, we selected two key genes [integrin-alpha-5 (Itga5); Receptor tyrosine-protein kinase (ErbB-4), Fig. 4] that were up-regulated and down-regulated after OGD, respectively. The gene discussed is ITGA5; the disease is ischemic stroke.