An overexpression of MMP2 has been reported in ESCC tissues as compared to adjacent normal epithelia52, and MMP3 SNP (MMP3 -1612 5A/6A) polymorphism was significantly associated with susceptibility to ESCC means ESCC subjects bearing 5A allele were more prone of getting ESCC as compared with 6A allele50. The gene discussed is MMP3; the disease is esophageal squamous cell carcinoma.