A further key area of research in our lab is study of neoplastic activity in the female reproductive tract, especially ovarian cancer, in relation to redox balance. Through investigation of human samples, we established myeloperoxidase (MPO), a mammalian peroxidase that catalyzes production of HOCl most abundant in neutrophils, and free iron as potential biomarkers for detection of ovarian cancer. Indeed, destruction of the MPO heme by self-generated HOCl during steady-state catalysis was found to be a major source of free iron, which contributes to oxidative stress and is widely associated with a number of disorders, including cancer. Furthermore, our research has indicated a close association of redox balance and development of cancer. We have found that leiomyoma of the uterus is characterized by defects in the cellular antioxidant system, especially deficiencies in superoxide dismutase and catalase. Furthermore, our studies also showed increases in expression of proteins associated with nicotinamide adenine dinucleotide phosphate oxidase, a major source of superoxide and oxidative stress, in uterine leiomyoma. States of heightened oxidative stress have also been associated with development of resistance to chemotherapeutic agents such as cisplatin in epithelial ovarian cancer. Our research has demonstrated the importance of various redox factors in regulating neoplasms in the female productive tract and has shown some possibilities for both preventative and active therapies.