TFPI2 and neoplasm: Aberrant DNA methylation of the CpG island region, i.e., the binding of a methyl group to the cytosine 5-carbon covalent bond of CpG dinucleotides, is associated with transcriptional silencing of TFPI2. Previous studies have reported that TFPI2 is frequently silenced by aberrant hypermethylation of its promoter in several tumour tissues [38–41].