GAS5 and hepatocellular carcinoma: Similarly, there have been researches that explored the functions of the five lncRNAs (DLGAP1-AS1, GAS5, LINC00665, TYMSOS, and ZFAS1) on tumorigenesis and progression of HCC or other tumors (Zhang et al., 2019; Zhou et al., 2019; Ding et al., 2020; Lin et al., 2020; Gu et al., 2021).