HEIH and hepatocellular carcinoma: One of the lncRNAs, lncRNA-HEIH (hepatocellular carcinoma upregulated EZH2-associated lncRNA), inhibits the expression of cell cycle regulatory genes via histone methylation mediated by enhancer of zeste homolog 2 (EZH2), a component of the PRC2 complex, and facilitates cell growth18.