Genetic information may play an increasingly important role in the personalized preventive medicine of the future. Whole-genome sequencing could open up new possibilities for identifying susceptibility to and risk of specific diseases even before symptoms appear, emphasizes Dr. Gyula Richárd Nagy, a clinical geneticist at Semmelweis University. However, to achieve this, we must first accurately "read" our genome—that is, the billions of DNA letters—with increasing precision. We must also ensure that the reference we are comparing it to is appropriate.