DNMT1 and cervical carcinoma: They also found that DNA methyltransferase 1 (DNMT1) in cervical cancer was significantly correlated with up- and downregulation of LINE-1 expression, and DNMT1 overexpression led to transcriptional repression of genes through hypermethylation, suggesting that LINE-1 correlates with endogenous factors (such as IL20 family genes and DNMT1) and exogenous factors (HPV) in cervical cancer.