HOXA9 and esophageal squamous cell carcinoma: They reported a higher number of deregulated HOX genes in ESCC, with nine genes exclusively expressed in tumors (HOXA10, HOXA13, HOXB7, HOXC4, HOXC8, HOXD9, HOXD10, and HOXD13) and three overexpressed in ESCC relative to NMSM (HOXA7, HOXA9, and HOXC6).