Dr. Jan Vijg has long been focused on studying genomic instability and its relationship with aging. More recently, Dr. Vijg began to focus on the long-standing problem of how to analyze DNA mutations in organs and tissues directly, across the genome. In 2012, the first assay based on whole genome sequencing of single cells or nuclei from various organisms, including human and mice, was published. Further optimization of the method's accuracy and its capability to deal with amplification errors occurred. There was the development of an assay to quantitatively analyze genome structural variation in genomic DNA. There is now the application of these advanced analysis methods to characterize the landscape of somatic mutations in different human tissues as a function of age and in relation to cancer susceptibility.