To study the possible occurrence of pericyte apoptosis during I/R injury as observed in cerebral ischemia (12), we stained 30 min, 60 min, and 24 h serial sections for PDGFRβ and for the active form of Caspase 3 (Casp3) (Figure 3). The gene discussed is PDGFRB; the disease is Cerebral ischemia.