Analysis of genomic DNAs isolated from Testisin-expressing (HeLa, SiHa and PEO4) and non-Testisin expressing (GCT27C-4, Tera-2, SW620 and U937) tumour cell lines showed that Testisin expressing cell lines contained very few methylated CpG sites (<20%) within this region, whereas the non-Testisin expressing cell lines showed a high percentage (>90%) of fully methylated CpG sites (Figure 1). Here, PRSS21 is linked to neoplasm.