HMGB1 and cancer: The CD133− cancer cells were then con-cultured with following agents for 7 days: (i) Different concentration of recombinant human HMGB1(rhHMGB1, 100, 200, 250, and 300 ng/mL); (ii) 20 Gy X-ray irradiated HMGB1 wide type cancer cells (iHMGB1+); (iii) 20 Gy X-ray irradiated HMGB1 knock down cancer cells (iHMGB1shRNA1); (iv) 20 Gy X-ray irradiated HMGB1 knock down cancer cells (iHMGB1shRNA2); (v) 250 ng/mL rhHMGB1+ iHMGB1shRNA1; (vi) 250 ng/mL rhHMGB1+ethyl pyruvate (EP, HMGB1 inhibitor); and (vii) PBS(control).