CDH1 and choriocarcinoma: It is demonstrated that CDH1 promoter 5′-CpG island is methylated to varying degrees in choriocarcinoma 35, prostatic carcinoma 18, 36, malignant melanoma 19, non-small cell lung cancer 20, hepatocarcinoma 21, and gastric cancer 23, of which hypermethylation is implicated in the epigenetic silencing of the CDH1 gene, leading to reduced or absent E-cadherin expression 12–25, 34–36.