Hepatitis viral infection causes a high level of ROS-induced DNA base damage [79], increasing the DNA methylation at the promoter of tumour suppressor genes including Cyclin-dependent kinase inhibitor 2A (CDKN2A, or p16) [80], E-cadherin (CDH1) [81], and Insulin-like growth factor binding protein 1 (IGFBP-1) [82]. Here, CDKN2A is linked to neoplasm.