To investigate whether the Testisin gene may be reactivated following demethylation of CpG sites and/or histone deacetylase inhibition, Testisin-nonexpressing tumour cell lines were treated with the demethylating agents, 5-azacytidine, 5-aza-2′-deoxycytidine, and/or the histone deacetylase inhibitor TSA. Here, PRSS21 is linked to neoplasm.