The expression of a group of metalloproteinases, including MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-10, MMP-11, MMP-13, MMP-14, and MT-1 MMP [9], was shown in the head and neck squamous cell carcinomas. The gene discussed is MMP3; the disease is head and neck squamous cell carcinoma.