HOXA7 and esophageal squamous cell carcinoma: Results: We found that copy number alterations and single nucleotide variations were rare, while seven HOX genes (HOXA2, HOXA7, HOXB13, HOXC9, HOXC10, HOXC13, and HOXD10) were significantly differentially expressed in ESCC compared to paired non-malignant mucosa.