STAT3 and lung cancer: The increasing serum levels of reactive oxygen species (ROS), nitric oxide (NO), inflammatory cytokines (e.g., IL-1β, IL-4, IL-6, and TNF-α), as well as the upregulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription 3 (STAT3), have been discovered in patients and animals with lung cancers [6, 7, 9, 10].