ROS promotes proliferation and growth of cancer cells through activating various cell signaling pathways, which are primarily mediated through the transcription factors nuclear factor-kappa B (NF-κB) and STAT3, hypoxia-inducible factor 1α (HIF1α), kinases, growth factors, cytokines and other proteins (Prasad et al., 2017). Here, STAT3 is linked to cancer.