HOTAIR and gastric cancer: We describe here a novel mechanism by which HOTAIR reduced expression of miR34a: (i) HOTAIR recruited and binded to PRC2 epigenetically silencing miR34a; (ii) which in turn activate C-Met and as a consequence resulting in the activation of Snail transcription; and (iii) upregulated Snail expression promotes EMT in gastric cancer (Figure 5f).