In addition to ROS, tumoral hypoxia is also responsible for HIF-1α upregulation, which in turn regulates the expression of proangiogenic, antioxidant, and goblet cell-associated factors, as well as mucin genes, allowing cancer cells to survive, proliferate, and undergo epithelial to mesenchymal transition (EMT) (16–18). The gene discussed is HIF1A; the disease is cancer.