MMP1 and head and neck squamous cell carcinoma: Gene profiling datasets showed that MMP-1 expression was strongly increased in HNSCC cases (e.g., 30.2-fold changes in a highly invasive HNSCC cell line, 13.9-fold changes in HNSCC cases and 57.6-fold changes in tongue squamous cell carcinoma cases (Table 1, Table 2 and Table 4, respectively)) [13,14,15].