TGFB1 and nasopharyngeal carcinoma: Accumulating evidence has shown that NPC patients have abnormal cytokine levels, including elevated levels of interleukin (IL)-6, IL-1 and tumor necrosis factor-alpha (TNF-α) as well as other molecules that are associated with inflammation process including soluble IL-2 receptor (sIL-2R), C-reactive protein (CRP) (15–17), and transforming growth factor-beta (TGF-β) (18, 19).