PTGS2 and lung carcinoma: Melatonin, a known natural antioxidant, showed to enhance the anti‐lung cancer effects of BBR through activating caspase and inhibiting transcription factors activator protein‐2 beta (AP‐2β), nuclear transcription factor κB (NF‐κB)/ cyclooxygenase 2 (COX‐2) and Akt/ extracellular signal‐regulated kinase (ERK) signalling pathways 8.