SFRP1 and head and neck squamous cell carcinoma: To determine how TET1 influenced Wnt/β-catenin signaling, the expression of Wnt pathway antagonists, including DACT (DACT1,2,3), SFRP (SFRP1,2,3), DKK (DKK1-3) family genes, and WNT proteins (include WNT1,3,3A,4, WAN5A, WNT5B, WNT7A, WNT7B) in HNSN (head and neck squamous cell normal tissues) and HNSC (head and neck squamous cell carcinoma) was analyzed.