SMPD1 and fibrosarcoma: However, genetic ASMase up-regulation in tumor microvasculature via Ad5H2E-PPE1(3x)-ASMase led to significant increase in endothelial apoptosis to 20±1%, 26±2% and 31±2% following 14.5 Gy, 17 Gy and 20 Gy, respectively (Fig. 6B; P<0.005 each), and to local cures in 30%, 60% and 80% of fibrosarcomas following these doses, respectively (Fig. 6A black lines; P<0.05 each vs. Ad5Empty-treated controls).