Chuong et al. used a theoretical model to compare the ability of family history and SNP-based methods to predict the risk of complex disease. Family-history-based methods were often more effective at predicting risk for more common heritable diseases, such as coronary artery disease, whereas SNP-based approaches had more power to predict less common disorders. The authors also highlight the difficulty in predicting the risk of many diseases using either method alone and advocate that these tests are complementary.