Rising rates of breast cancer are of concern to everyone in medicine. To what can we attribute this disturbing trend? For answers, host Dr. Lisa Mazzullo welcomes Dale Sandler, PhD, MPH, chief of epidemiology at the National Institute for Environmental Health Sciences (NIEHS), and principal investigator of the NIEHS Sister Study, a bold initiative to evaluate 50,000 sisters of women with breast cancer, measuring a confluence of environmental factors against their disease risk.