The research, published in Nature, suggests that inherited genetic differences shape not only the risk of developing cancer but also how cancers evolve after DNA damage occurs. To investigate this, researchers bred four genetically distinct strains of mice with different natural susceptibilities to liver cancer. DEN is found in tobacco smoke and certain processed foods and is known to damage DNA in liver cells. The team then analyzed nearly 600 liver tumors, sequencing their genomes and studying gene activity to reconstruct how each cancer developed. Although the study was conducted in mice, the results suggest that inherited genetic differences could play an important role in determining individual cancer risk in humans.