HOTAIR and lip and oral cavity carcinoma: To further investigate whether HOTAIR plays a role in maintaining CSCs hallmarks, loss-of-function mutation was generated in GNM and Ca9-22 sphere-forming oral cancer stem cells using small hairpin RNA targeting HOTAIR (sh-HOTAIR-1 and sh-HOTAIR-2), and lentiviral vector expressing shRNA against luciferase (sh-Luc) was used as control.