HOTAIR (for HOX transcript antisense RNA) is a human gene located on chromosome 12. It is the first example of an RNA expressed on one chromosome that has been found to influence transcription on another chromosome.
It is an important factor in the epigenetic differentiation of skin over the surface of the body. Skin from various anatomical positions is distinct, e.g. the skin of the eyelid differs markedly from that on the sole of the foot.
HOTAIR is highly expressed in metastatic breast cancers. High levels of expression in primary breast tumours are a significant predictor of subsequent metastasis and death. This is partially due to HOTAIR-mediated overexpression of the HER2 oncogene through sequestration of miR-133-3p, which is a negative regulator of HER2 expression. In cells, especially those that over express PRC2, the prevention of HOTAIR expression leads to a reduction in invasive potential of that cell.  It is also involved in esophageal squamous cell carcinoma.
^Chen FJ, Sun M, Li SQ, Wu QQ, Ji L, Liu ZL, Zhou GZ, Cao G, Jin L, Xie HW, Wang CM, Lv J, De W, Wu M, Cao XF (Nov 2013). "Upregulation of the long non-coding RNA HOTAIR promotes esophageal squamous cell carcinoma metastasis and poor prognosis". Molecular Carcinogenesis. 52 (11): 908–15. doi:10.1002/mc.21944. PMID24151120.
Yang Z, Zhou L, Wu LM, Lai MC, Xie HY, Zhang F, Zheng SS (May 2011). "Overexpression of long non-coding RNA HOTAIR predicts tumor recurrence in hepatocellular carcinoma patients following liver transplantation". Annals of Surgical Oncology. 18 (5): 1243–50. doi:10.1245/s10434-011-1581-y. PMID21327457.
Nie Y, Liu X, Qu S, Song E, Zou H, Gong C (Apr 2013). "Long non-coding RNA HOTAIR is an independent prognostic marker for nasopharyngeal carcinoma progression and survival". Cancer Science. 104 (4): 458–64. doi:10.1111/cas.12092. PMID23281836.