Inconsistent statistical results have been reported even in immunohistochemical evaluations of cancers other than HNSCC: although a significant inverse correlation between Cox-2 and E-cadherin expressions was seen in bladder cancer [41], no correlation between them was revealed in gastric cancer [40], the latter of which is in agreement with our result assessed by quantitative real-time PCR. This evidence concerns the gene CDH1 and head and neck squamous cell carcinoma.