Although we showed that ROS scavenging or inhibition reduces the proliferation of cancer cells, it is important to bear in mind that we also observed that ROS scavenging or Nox4 inhibition, in oncogene-expressing cells that have not yet accumulated DNA damage or bypassed OIS, may in fact allow these oncogene-expressing cells to proliferate without ‘hyperproliferating' (see Figure 1a). The gene discussed is NOX4; the disease is cancer.