EHMT2 or G9a is a histone methyl transferase that primarily catalyzes mono- and dimethylation of histone H3K9 to afford H3K9me1/me2, being overexpressed in several cancers, including head and neck squamous carcinoma, breast cancer, and aggressive ovarian and bladder cancers [26]. The gene discussed is EHMT2; the disease is urinary bladder carcinoma.