MPSNT3 (A) and JJ012 (B) tumors were irradiated with 30 Gy or 15 Gy after 1 h pre-treatment with Pazopanib (100 mg/kg p.o.). Mouse serum was collected at 1 h and 6 h after radiation and ASMase activity was measured by quantifying conversion of (14C)sphingomyelin to the product (14C)phosphocholine. Data is mean ± SD. *p < 0.05 and **p < 0.01.