Pazopanib (100 mg/kg p.o.) was administered to MPNST3 bearing ICR-SCID mice (A, C) and JJ012 sarcoma bearing SCID mice (B, D) and after 1 h tumors were irradiated with 30 Gy and 15 Gy, respectively. Tumors were removed 6 h after irradiation, fixed in 4% paraformaldehyde, and embedded in paraffin. 5-mm sections of tumor specimens were double stained with MECA-32 (red), to detect TEC, and cleaved caspase-3 , to identify apoptotic cells. Data (mean ± SD) are collected from 5 mice per group with 1000 endothelial cells evaluated. Scale bar, 50 μm. (*p < 0.05).