HOTAIR and esophageal squamous cell carcinoma: Zhang et al. initially identified 3 tagSNPs of HOTAIR gene (i.e., rs920778, rs1899663 and rs4759314) and evaluated their associations on esophageal squamous cell carcinoma (ESCC) risk; and they found that SNP rs920778 was dramatically related to increased ESCC risk and functional study demonstrated an allele-specific effect on the intronic enhancer activity of HOTAIR [16].