Accordingly, irradiation of bulky tumors may yield a fraction of cancer cells that undergoes cell death without the activation of ROS-triggered survival pathways, whereas another fraction of cancer cells, located mainly at the deep periphery of the target tissue, may suffer from oxidative stress but survive as a result of ROS-mediated activation of e.g., NF-κB-mediated survival pathways. Here, NFKB1 is linked to cancer.