AQP4 expression was investigated by IHC staining at day 4 post-MCAO and revealed to be upregulated in the stroke control rats, as evidenced by intense expression in the neuropil and perivascular areas of the cortex and striatum regions (Fig. 4A), and this expression in stroke control was significantly higher (1.17 ± 0.31; p = 0.033) as compared to that in healthy control rats (0.20 ± 0.20) (Fig. 4B). The gene discussed is AQP4; the disease is stroke disorder.