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 digestive system neoplasm.