Crucially, the DSBs caused by the cut-and-run reaction colocalize with many structural variants (SVs) found in ETV6–RUNX1 acute lymphoblastic leukaemia (ALL)19 and map to frequently mutated genes in B cell precursor ALLs (BCP-ALLs)18, implying that cut-and-run contributes to the development of BCP-ALL. Here, ETV6 is linked to acute lymphoblastic leukemia.