HOTAIR and breast cancer: Recently, the up-regulation of HOTAIR was observed in several cancers, including breast cancer [7,28-30], hepatocellular carcinoma [11,31], colorectal cancer (CRC) [9,32], pancreatic cancer [33], non-small cell lung cancer (NSCLC) [34] and esophageal squamous cell carcinoma (ESCC) [32,33].