HOXA9 is part of the A cluster on chromosome 7, and has been shown to act as an oncogene in acute myeloid leukemia, whereas silencing of HOXA9 by promoter methylation has been detected in several solid tumors such as breast, lung, ovarian and oral cancer [17,18,19,20,21]. The gene discussed is HOXA9; the disease is lip and oral cavity carcinoma.