Moreover, we established gefitinib-resistant ovarian cancer cells, A2780R and OVCAR-3R from the gefitinib-sensitive human ovarian cancer cell lines A2780 and OVCAR-3, and combined treatment with gefitinib and 6-shogaol overcomes gefitinib resistance via the activation of ER stress and the suppression of EMT processes such as the inhibition of E-cadherin and the increase in N-cadherin, vimentin, Slug, and Snail (Figure 9G). This evidence concerns the gene CDH1 and ovarian carcinoma.