Years ago, many scientists assumed that a woman's heart worked pretty much the same as a man's. But as more women entered the male-dominated field of cardiology, many such assumptions vanished, opening the way for new approaches to research and treatment. A similar shift is underway in the study of Alzheimer's disease. It has long been known that more women than men get the deadly neurodegenerative disease, and an emerging body of research is challenging the common wisdom as to why. Although the question is by no means settled, recent findings suggest that biological, genetic and even cultural influences may play heavy roles. Of the more than 5 million people in the United States who have been diagnosed with Alzheimer's, the leading cause of dementia, two-thirds are women. Because advancing age is considered the biggest risk factor for the disease, researchers largely have attributed that disparity to women's longer life spans. The average life expectancy for women is 81 years, compared with 76 for men. And even after taking age into account, women are more at risk. With the number of Alzheimer's cases in the United States expected to more than triple by 2050, there is a greater need to understand the underlying reasons women are more prone to the disease and to develop gender-specific treatments. The area of inquiry has been growing in part because of a push by female Alzheimer's researchers, who have formed a group to advocate for a larger leadership role in the field and more gender-specific research.