In this study we analyzed the expression of DUSP6 in SP and NSP cells, where it is differentially expressed, and from chemotherapy-resistant or -sensitive ovarian cancer cell lines to deduce the role of DUSP6 in negatively regulating ERK1/2 activity during the cell cycle, which leads to G0/G1 arrest and chemotherapy-resistance. This evidence concerns the gene MAPK3 and ovarian carcinoma.