MMP9 and esophageal squamous cell carcinoma: The HMGA2 protein is a non-histone chromatin factor involved in DNA repair [83], aggressiveness of esophageal squamous cell carcinoma [84], epithelial-to-mesenchymal transition (EMT) process [85,86], and the up-regulation of EMT-related genes such as TGF-beta, SNAIL1, SLUG, MMP2, and MMP9 in RMS patients [87].