HOTAIR and esophageal squamous cell carcinoma: Recently, the up-regulation of HOTAIR was observed in several cancers, including breast cancer [14,16,17], hepatocellular carcinoma [18], colorectal cancer (CRC) [19], pancreatic cancer [20], non-small cell lung cancer (NSCLC) [21], and esophageal squamous cell carcinoma (ESCC) [22,23].