HOTAIR and cancer: The high expression of HOTAIR promotes OSCC cells metastases by recruiting the enhancer of zeste homolog 2 and repressing E-cadherin.[63] HOTAIR upregulates human epithelial growth factor receptor 2 expression, thereby enhancing proliferation and migration of gastric cancer cells by sponging miR-331–3p.[42] In addition, HOTAIR enhances migration and invasion of breast cancer cells by inhibiting miR-7 expression.[76] Several factors might affect HOTAIR expression in cancers.