Many factors play a role in the development of breast cancer in women, but the greatest predictor is the presence of mutations in tumor-suppressing genes (BRCA1/BRCA2). Nevertheless, there remains a skepticism surrounding the statistical correlation between such mutations and the eventual diagnosis of breast cancer given the effects of ascertainment bias in the selection of candidates for genetic testing. CHAS Fellow Olufunmilayo I. Olopade was part of a team that reviewed the pedigrees of families who were included in research by the Cancer Risk Clinic at the University of Chicago between 1992 and 2013 so as to hopefully provide a more accurate picture as to the role of BRCA1 and BRCA2 in the development of cancer.