PRSS8 and neoplasm: Thus, Testisin may be added to an emerging list of tumour suppressor genes that are silenced by DNA hypermethylation, including prostasin (Chen and Chai, 2002), E-cadherin (Melki et al, 2000; Nakayama et al, 2001), normal epithelial cell-specific 1 (NES1) (Li et al, 2001) and COX-2 (Kikuchi et al, 2002).