Additionally, we analyzed seven genes which have previously been reported to be hypermethylated in ovarian cancer, including APC, CDH13, MGMT, MLH1, p14ARF, p16INK4a, and RASSF1A. For RASSF1A [27,28], APC [29,30], and CDH13 [31], we found comparable methylation frequencies to previous reports, which have also shown that promoter hypermethylation of these genes are associated with loss of gene expression in various tumour types [31-33]. Here, CDH13 is linked to neoplasm.