O-charoenrat and Khantapura [58] have reported that subjects with the MMP2 CC genotype were associated with a significantly increased risk [adjusted OR 1.97; 95% confidence interval (95% CI), 1.23–3.15] for developing HNSCC compared with those with the variant genotype (-1306 CT or TT). This evidence concerns the gene MMP2 and head and neck squamous cell carcinoma.