Medical and science researchers continue to try to get at the root cause of racial and ethnic health disparities. Why are advanced breast cancer rates so much higher among certain populations, particularly African-American women? Why are colon cancer rates significantly higher among Native Americans? Years of research have yielded many theories but no firm answers to several of these kinds of questions. Earlier this year, the National Institutes of Health (NIH) awarded grants to 10 Centers for Population Health and Health Disparities. NIH says the grants are designed "to better understand and address inequities associated with the two leading causes of death in the United States--cancer and heart disease." Each center will receive approximately $10 million over five years.