I graduated from the University of Utrecht (The Netherlands) in 1978 with a Doctoral Degree in Veterinary Science (D.V.Sc.) and received in 1989 a Doctorate Degree (Ph.D.) in Experimental Pathology form the same University. I am a Board Certified Laboratory Animal Pathologist (Netherlands Association of Pathologists & Royal Netherlands Veterinary Association) and hold Certification in Laboratory Animal Science and am a Certified Animal Welfare Officer (ex article 14, Netherlands Experiments on Animals Act) both from the Netherlands Ministry of Welfare, Public Health, and Culture. I was Research Scientist-Toxicologic Pathologist in the Department of Biological Toxicology, Institute CIVO-Toxicology and Nutrition TNO, Zeist, The Netherlands from 1978-1988. From 1985-2006, I have been on the Faculty of the Department of Environmental Medicine of New York University (NYU) School of Medicine, since 2000 as Professor of Environmental Medicine and Urology. Since 2006, I have been at the University of Illinois at Chicago College of Medicine in the Department of Pathology. I have published over 150 articles and book chapters about my research, which has focused on causation and prevention of prostate cancer. My current research interests include prostate cancer chemoprevention, both preclinical research and human clinical trials; animal models of prostate cancer; mechanisms of hormonal prostate carcinogenesis with a focus on the role of estrogens and androgens; hormonal carcinogenesis of the prostate gland and animal models of prostate carcinogenesis; endocrine disruptors and prostate cancer; and anticancer properties of naturally occurring substances and African medicinal plants. I am also actively involved in capacity building in health sciences and medicine in Africa.