HOTAIR and glioma: Take HOTAIR for another example, EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2) and is involved in repressing gene expression through methylation of histone H3 on lysine 27 (H3K27) [56], EZH2 (predominant PRC2 complex component) inhibition blocked cell cycle progression in glioma cells, which is consistent with the effects elicited by HOTAIR siRNA.