GAS5 and hepatocellular carcinoma: Specifically, miR-21 modulates the expression of 23 lncRNAs (Figure 1a), including suppressing the expression of growth arrest-specific 5 (GAS5) in the breast tumor specimens, promoting the expression of small nucleolar RNA host gene 1, and activating Akt (protein kinase B) pathway in hepatocellular carcinoma (HCC) cells [15].