Furthermore, histone methyltransferases, such as SET and MYND domain-containing 3 and suppressor of variegation 3–9 homolog 1 (SUV39h1), are also known to be upregulated in HCC tissues [129,130,134,141], and their expression is enhanced by HBx [134,136]. Here, SUV39H1 is linked to hepatocellular carcinoma.