This study investigates the clonal evolution in relapsed acute myeloid leukemia (AML) using whole-genome sequencing. The researchers sequenced primary tumors and relapse genomes from eight AML patients, validating hundreds of somatic mutations through deep sequencing. They identified novel recurrently mutated genes such as WAC, SMC3, DIS3, DDX41, and DAXX. Two major clonal evolution patterns were observed: (1) the founding clone in the primary tumor gained mutations and evolved into the relapse clone, or (2) a subclone of the founding clone survived initial therapy, gained additional mutations, and expanded at relapse. Chemotherapy failed to eradicate the founding clone in all cases. The comparison of relapse-specific versus primary tumor mutations revealed an increase in transversions, likely due to DNA damage caused by cytotoxic chemotherapy. These findings highlight the role of chemotherapy in generating new mutations and promoting clonal evolution, which may contribute to relapse. The study underscores the need for targeted therapies to avoid the use of mutagenic cytotoxic drugs.This study investigates the clonal evolution in relapsed acute myeloid leukemia (AML) using whole-genome sequencing. The researchers sequenced primary tumors and relapse genomes from eight AML patients, validating hundreds of somatic mutations through deep sequencing. They identified novel recurrently mutated genes such as WAC, SMC3, DIS3, DDX41, and DAXX. Two major clonal evolution patterns were observed: (1) the founding clone in the primary tumor gained mutations and evolved into the relapse clone, or (2) a subclone of the founding clone survived initial therapy, gained additional mutations, and expanded at relapse. Chemotherapy failed to eradicate the founding clone in all cases. The comparison of relapse-specific versus primary tumor mutations revealed an increase in transversions, likely due to DNA damage caused by cytotoxic chemotherapy. These findings highlight the role of chemotherapy in generating new mutations and promoting clonal evolution, which may contribute to relapse. The study underscores the need for targeted therapies to avoid the use of mutagenic cytotoxic drugs.