The results showed that catalase inhibited the enhanced tumour cell adhesion after X–XO preincubation effectively as well, that is, for HT29 adhesion decreased from 167 to 141% (P<0.05), for Caco2 from 158 to 113% (P<0.01), and for PanC1 from 299 to 163% (P<0.01). This evidence concerns the gene CAT and neoplasm.