HOTAIR and respiratory system cancer: However, both relationships were only observed in cancers of the digestive system in previous analyses.[18,20,21] We found that high HOTAIR expression was related to poor differentiation in estrogen-dependent cancers and OSCCs, although the correlation was not identified in previous studies.[18–21] Our results showed that HOTAIR expression correlated with a larger tumor size, though the statistical significance was only found in cancers of the respiratory system and there was a publication bias, suggesting that large-scale investigations were required.