If you are a U.S. resident between 35 and 74 years old, have a blood sister who had breast cancer and have never had the disease yourself, you could help researchers learn more about the illness, which affects 1 in 8 women. The Sister Study is enrolling 50,000 women in an ambitious, first-of-its-kind effort to learn what role the environment and genetics play on a woman’s chances of developing breast cancer. The study’s results may be especially important for black women, who are less likely to develop breast cancer, but more likely to die from it.

Enrollment is simple: Call 877.4SISTER or log on to www. sisterstudy.org and fill out a questionnaire. Investigators will collect samples of your blood, toenails, urine and household dust. Even simpler: You don’t have to leave home—researchers come to you.