Cell count of viable adipose-derived stem cells (ASC), human microvascular endothelial cells (HDMEC) and the co-culture of ASC and HDMEC 48 h after irradiation with 2 to 12 Gy compared to unirradiated control cells. Error bars represent standard deviation. Statistical significance was set at p < . 05 (*). P values < .01 (**) and p values < .001 (***) were indicated respectively.