Only one HOX gene, HOXD10, seems to act almost exclusively as a tumour suppressor, albeit with a notable exception in head and neck squamous cell carcinoma (HNSCC).109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121. This evidence concerns the gene HOXD10 and head and neck squamous cell carcinoma.