CDH1 and neoplasm: After bovine oocyte extract treatment, the DNA methylation and repressive histone modifications were reduced, and activating histone modification H3K4me3 was increased at the promoters of tumour suppressor genes RUNX3 and CDH1. These epigenetic changes induce an open chromatin structure at RUNX3 and CDH1 promoters, facilitating their access by transcription factors and thus activating transcription.