Immunofluorescence staining (Fig. 4a) showed that GFAP-immunoreactive cells in the peri-infarct area of ipsilateral cortex and striatum that exhibited the typical features of reactive astrocytes (Fig. 4b) underwent progressively an augmentation in number 6 h and 24 h after cerebral ischemia (Fig. 4c). The gene discussed is GFAP; the disease is brain ischemia.