In CAL27 cells induced by low-dose arecoline, we observed promoter methylation of SALL3, IRF8, TSHZ3 and CRMP1. SALL3 methylation could clearly distinguish HNSCC from adjacent normal mucosal tissue, thus being an independent predictor of poor survival in HNSCC [55]. This evidence concerns the gene SALL3 and head and neck squamous cell carcinoma.