Cancer Types Studied (IMAGE) University of East Anglia Caption An international team systematically investigated the DNA found within more than 2,600 tumor samples from patients with 38 different types of cancer. They discovered traces of viruses in 13% of the samples studied, and also further identified some of the mechanisms that viruses use to trigger carcinogenic mutations. Credit Pan-Cancer Analysis of Whole Genomes Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.