Since it has been shown [32, 33] that S100A4 regulates the expression of invasion- and migration-associated genes, such as metalloproteases (MMPs), we next analyzed the mRNA levels of MMP2, which is known to be regulated by S100A4 in esophageal squamous cell carcinoma [34]. This evidence concerns the gene S100A4 and esophageal squamous cell carcinoma.