TF and nasopharyngeal carcinoma: By down-regulating the expression of Secreted Protein, Acidic and Rich in Cysteine (SPARC), TF sex determining region Y-box 5 (SOX-5) functions in the progression of NPC and may be used as a predictor for poor NPC prognosis.14, 15 Although these studies have been performed to investigate NPC, the mechanisms of NPC still remain unclear.