HOTTIP and osteosarcoma: Up-regulated expression of HOTTIP has been reported in different cancers, including hepatocellular carcinoma [6], pancreatic cancer [7], colorectal cancer [8, 9], osteosarcoma [10], tongue squamous cell carcinoma [11] and gastric cancer [12].All these data indicated that HOTTIP plays an potential oncogenic role in these tumors by promoting cell proliferation, inhibiting cell apoptosis and increasing cell migration.