STAT3 and cancer: Such mechanism for cancer development, in the presence of chronic inflammation, involves the continuous presence of cytokines, chemokines, ROS (reactive oxygen species), oncogenes, COX-2 (cyclooxygenase-2), 5-LOX (5-lipoxygenase), and MMPs (metalloproteinases) and activation of important transcription factors such as NF-ĸB (nuclear factor-ĸB), STAT-3 (signal transducer and activator of transcription 3), AP-1 (activator protein-1), and HIF-1α (hypoxia-inducible factor 1-alpha) [7, 8].