Who is your emergency contact? The answer to that question, standard in every doctor’s office, has now been used to predict the role of genes in hundreds of conditions, from diabetes to high cholesterol. A new study combined the emergency contact information of 2 million New Yorkers with their medical data to form family trees of heritability—all without ever looking at a patient’s DNA. The approach could be used by clinics widely to predict a person’s disease risks, if patients agree to let their data be used in this way. Read more.