We applied three thyroid cancer cell lines (MDA-T32, MDA-T41 and K1) to investigate the phenotypic influence after gain or loss of HOTAIR. The Cancer Genome Atlas (TCGA) database were utilised to select candidate genes possibly regulated by HOTAIR with validation in the cellular system and immunohistochemical (IHC) staining of PTC tissues. The gene discussed is HOTAIR; the disease is thyroid gland carcinoma.