It is worth noting that the transcript levels of the endogenous hypoxia marker CA9 are inversely correlated with the levels of lncRNA-LET in primary HCC tissues, and downregulated expression of lncRNA-LET is associated with HCC metastasis (Olive et al., 2001[76]; Yang et al., 2013[108]). The gene discussed is CA9; the disease is hepatocellular carcinoma.