For example, hypermethylation of the Hhip gene promoter has been found in several tumor cell lines, including HCC, pancreatic cancer, MB, and various gastrointestinal tumors.392–395 Down-regulation of Hhip expression using siRNA resulted in a significant increase in colon cancer cell growth and invasion in vitro.395 Therefore, adjustment of Hhip level allows regulation of cancer development. This evidence concerns the gene HHIP and hepatocellular carcinoma.