Furthermore, we found a reverse regulation of DNMT1 by siRNA in the resistance to paclitaxel induced by UBC13 down-regulation in ovarian cancer cells and a prolonged DNMT1 protein half-life in the paclitaxel resistant ovarian cancer cells, suggesting that DNMT1 participates in the process of UBC13 regulation of the sensitivity to paclitaxel in ovarian cancer cells. This evidence concerns the gene DNMT1 and ovarian cancer.