DEHP treatment of endometrial cells in vitro has been shown to increase ROS, which indicates that DEHP can induce oxidative stress in human endometrial cells [60] and DEHP-associated endometrial stromal cell alterations may be associated with the progression of the pathogenesis of endometriosis [61]. In vitro exposure to DEHP can lead to the establishment of endometriosis by increasing the invasive and proliferative activities of endometrial cells because DEHP can increase metalloproteinase- (MMP-) 2 and MMP-9 activities and cellular invasiveness. The gene discussed is MMP9; the disease is endometriosis.