TUG1 and hepatocellular carcinoma: The long non‐coding RNA TUG1 was first identified as being required for the differentiation of mouse retinal cells,[16] it is also involved in the regulation of mitochondrial bioenergetics in diabetic nephropathy,[17] as well as male fertility.[18] TUG1 is upregulated in a variety of cancers including HCC, and the cancer biological functions of TUG1 have been well studied.[19, 20] However, how TUG1 is upregulated in cancers and the effects of its upregulation on the tumor immune microenvironments are incompletely understood.