IRX1 and head and neck squamous cell carcinoma: Bennett et al (7) reported an association between the HNSCC and hypermethylation of IRX1 in accordance with our results, and four other genes (FUSSEL18, EBF3, SLC5A8 and SEPT9), but not SLC5A8; we did not find any methylated CpG on the promoter regions of the last five genes.