A collaborative study from the Wellcome Sanger Institute and University of Cambridge has delineated distinct mutational signatures in normal blood cells associated with various chemotherapy agents. Whole genome sequencing of blood samples from treated patients revealed specific DNA damage patterns, notably high mutation burdens from platinum-based drugs such as carboplatin and cisplatin. The findings advance understanding of chemotherapy’s mutagenic impacts on healthy tissues, providing a genomic basis to optimize therapeutic regimens and mitigate long-term risks including secondary malignancies.