EHMT2 and esophageal squamous cell carcinoma: Studies have revealed that G9a is overexpressed in a number of cancers, including esophageal squamous cell carcinoma, hepatocellular carcinoma, brain cancer, multiple myeloma, and aggressive ovarian carcinoma; and overexpressed G9a is found to be associated with enhanced proliferation and metastasis of various cancer cells [7, 8].