ERBB2 and ovarian carcinoma: In the present study, we mainly focused on multiple epigenetic mechanisms involved in the regulation of DNMT genes in normal and cancerous ovaries of laying hens, which are the most relevant animal model to identify biomarkers of human ovarian cancer such as CA125, cytokeratin, EGFR, Lewis Y, and erbB-2 and also expressed in carcinoma cells, but not normal cells in ovaries of laying hens [15], [16], [17], [18].